diff --git a/.github/workflows/asv.yml b/.github/workflows/asv.yml
deleted file mode 100644
index 4856306bfd..0000000000
--- a/.github/workflows/asv.yml
+++ /dev/null
@@ -1,95 +0,0 @@
-# Runner information:
-# CPU: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
-# GPU: NVIDIA GeForce RTX 2060
-
-name: asv-benchmarks
-
-env:
-  OUTPUT_PATH: ${{ github.workspace }}
-  ENVHOME: "/home/devito/environments"
-
-on:
-  workflow_dispatch:
-    inputs:
-      tags:
-        description: 'Run ASV'
-  # Trigger the workflow on push to the master branch
-  push:
-    branches:
-      - master
-
-jobs:
-
-  # Run the asv benchmarks on the self-hosted runner
-  benchmarks:
-    name: benchmarks
-    runs-on: [self-hosted, asv]
-
-    env:
-      DEVITO_ARCH: "gcc-9"
-      DEVITO_LANGUAGE: "openmp"
-      DEVITO_BENCHMARKS: "1"
-      DEVITO_LOGGING: "PERF"
-      OMP_NUM_THREADS: "8"
-      CC: "gcc-9"
-      CXX: "g++-9"
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v2.3.2
-
-    - name: Set VIRTUAL_ENV
-      run: |
-        echo "VIRTUAL_ENV=$ENVHOME/asv" >> $GITHUB_ENV
-        echo "PATH=$VIRTUAL_ENV/bin:$PATH" >> $GITHUB_ENV
-
-    - name: Set PATH
-      run: |
-        echo "PATH=$VIRTUAL_ENV/bin:$PATH" >> $GITHUB_ENV
-
-    - name: Install dependencies
-      run: |
-        pip install --upgrade pip
-        pip install -e .
-        pip install --upgrade asv
-
-    - name: Setup asv
-      run: |
-        asv machine --config benchmarks/regression/asv.conf.json --machine i7-6700K --os ubuntu-20.10 --arch x86-64 --cpu i7-6700K --num_cpu 8 --ram 16GB
-
-    - name: Run benchmarks
-      run: |
-        asv run -v --strict --show-stderr --config benchmarks/regression/asv.conf.json --cpu-affinity 0-7 --machine i7-6700K
-
-    - name: Checkout asv-results branch
-      uses: actions/checkout@v2.3.2
-      with:
-        ref: asv-results
-        clean: false
-
-    - name: Commit benchmarks results
-      run: |
-        git config --local user.email "action@github.com"
-        git config --local user.name "GitHub Action"
-        git add -f benchmarks/regression/.asv/results/
-        git status
-        git commit -m "Commit ASV results"
-
-    - name: Push benchmarks results to the asv-results branch
-      uses: ad-m/github-push-action@master
-      with:
-        branch: asv-results
-        force: true
-        github_token: ${{ secrets.GITHUB_TOKEN }}
-
-    - name: Create results (html)
-      run: |
-        asv publish --config benchmarks/regression/asv.conf.json
-
-    - name: Deploy results to devitocodes/devito-performance/gh-pages
-      uses: peaceiris/actions-gh-pages@v2.5.0
-      env:
-        ACTIONS_DEPLOY_KEY: ${{ secrets.ACTIONS_DEPLOY_KEY }}
-        EXTERNAL_REPOSITORY: devitocodes/devito-performance
-        PUBLISH_BRANCH: gh-pages
-        PUBLISH_DIR: ./benchmarks/regression/.asv/html
diff --git a/.github/workflows/cancel.yml b/.github/workflows/cancel.yml
deleted file mode 100644
index 252d4da389..0000000000
--- a/.github/workflows/cancel.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-name: Cancel
-
-on: [push]
-
-jobs:
-  cancel:
-    name: 'Cancel Previous Runs'
-    runs-on: ubuntu-latest
-    timeout-minutes: 3
-    steps:
-      - uses: styfle/cancel-workflow-action@0.4.0
-        with:
-          # Ids to cancel core/mpi/gpu/examples/tutorials
-          # https://api.github.com/repos/devitocodes/devito/actions/workflows
-          workflow_id: 167582, 203470, 203471, 434862, 501517
-          access_token: ${{ github.token }}
\ No newline at end of file
diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
deleted file mode 100644
index 67bf09c285..0000000000
--- a/.github/workflows/docker-publish.yml
+++ /dev/null
@@ -1,131 +0,0 @@
-name: Publish docker image
-
-on:
-  release:
-    types: [published]
-  push:
-    branches:
-      - master         # Push events on master branch
-
-jobs:
-  deploy-docker-cpu:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout devito
-        uses: actions/checkout@v2
-
-      - name: Check event name
-        run: echo ${{ github.event_name }}
-
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v1.0.2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1.1.2
-
-      - name: Login to DockerHub
-        uses: docker/login-action@v1
-        with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
-
-      - name: CPU image
-        if: github.event_name == 'push'
-        uses: docker/build-push-action@v2.4.0
-        with:
-          context: .
-          file: ./docker/Dockerfile
-          push: true
-          tags: devitocodes/devito:cpu-dev
-
-      - name: CPU image release
-        if: github.event_name == 'release'
-        uses: docker/build-push-action@v2.4.0
-        with:
-          context: .
-          file: ./docker/Dockerfile
-          push: true
-          tags: |
-            devitocodes/devito:cpu-latest
-            devitocodes/devito:cpu-${{ github.event.release.tag_name }}
-
-  deploy-docker-gpu:
-    runs-on: [self-hosted, gpu, docker]
-
-    steps:
-      - name: Checkout devito
-        uses: actions/checkout@v2
-
-      - name: Check event name
-        run: echo ${{ github.event_name }}
-
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v1.0.2
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1.1.2
-
-      - name: Login to DockerHub
-        uses: docker/login-action@v1
-        with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
-
-      - name: GPU image
-        if: github.event_name == 'push'
-        uses: docker/build-push-action@v2.4.0
-        with:
-          context: .
-          file: ./docker/Dockerfile.nvidia
-          push: true
-          tags: devitocodes/devito:gpu-dev
-
-      - name: GPU image release
-        if: github.event_name == 'release'
-        uses: docker/build-push-action@v2.4.0
-        with:
-          context: .
-          file: ./docker/Dockerfile.nvidia
-          push: true
-          tags: |
-            devitocodes/devito:gpu-latest
-            devitocodes/devito:gpu-${{ github.event.release.tag_name }}
-
-  # Comment out 'cpu-latest' until next release
-  test-cpu-image:
-    needs: deploy-docker-cpu
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-      matrix:
-        #im-name: [cpu-dev, cpu-latest]
-        im-name: [cpu-dev]
-
-    steps:
-        - name: Run simple test
-          run: |
-             docker pull 'devitocodes/devito:${{ matrix.im-name }}'
-             docker run --rm --name testrun 'devitocodes/devito:${{ matrix.im-name }}' pytest tests/test_operator.py
-
-  test-gpu-image:
-    needs: deploy-docker-gpu
-    runs-on: [self-hosted, gpu, docker]
-
-    strategy:
-      fail-fast: false
-      matrix:
-        #im-name: [gpu-dev, gpu-latest]
-        im-name: [gpu-dev]
-
-    steps:
-        - name: Run simple test
-          run: |
-             docker pull 'devitocodes/devito:${{ matrix.im-name }}'
-             docker run --gpus all --rm --name testrun 'devitocodes/devito:${{ matrix.im-name }}' pytest tests/test_gpu_openacc.py
-
-        # NOTE: Suitable for the time being but will need to modify when we switch runners
-        - name: Clean
-          run: |
-            docker system prune -a -f
diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
deleted file mode 100644
index cd4055e5bc..0000000000
--- a/.github/workflows/documentation.yml
+++ /dev/null
@@ -1,34 +0,0 @@
-name: Documentation
-
-on:
-  push:
-    branches:
-      - master         # Push events on master branch
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v1
-    - name: Set up Python
-      uses: actions/setup-python@v1
-      with:
-        python-version: '3.x'
-    - name: Install Sphinx
-      run: |
-        python -m pip install --upgrade pip
-        pip install sphinx sphinx_rtd_theme
-        pip install -e .
-
-    - name: Generate documentation
-      working-directory: docs
-      run: make html
-
-    - name: Deploy
-      uses: peaceiris/actions-gh-pages@v2
-      env:
-        PERSONAL_TOKEN: ${{ secrets.PERSONAL_TOKEN }}
-        PUBLISH_BRANCH: gh-pages
-        PUBLISH_DIR: ./docs/_build/html
diff --git a/.github/workflows/examples-mpi.yml b/.github/workflows/examples-mpi.yml
deleted file mode 100644
index fea29345d9..0000000000
--- a/.github/workflows/examples-mpi.yml
+++ /dev/null
@@ -1,64 +0,0 @@
-# Runner information:
-# CPU: Intel(R) Xeon(R) CPU E5-2640 0 @ 2.50GHz (24 cores)
-
-name: Examples-mpi
-
-env:
-  OUTPUT_PATH: ${{ github.workspace }}
-  ENVHOME: "/home/devito/environments"
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  build:
-    name: Examples with mpi
-    runs-on: ["self-hosted", "mpi", "examples"]
-
-    env:
-      DEVITO_MPI: "1"
-      DEVITO_LANGUAGE: "openmp"
-      OMP_NUM_THREADS: "2"
-      DEVITO_ARCH: "gcc"
-      CC: "gcc"
-      CXX: "g++"
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v2.3.2
-
-    - name: Set environment
-      run: |
-        source $ENVHOME/devito-cpu-mpi/bin/activate
-        echo "PATH=$PATH" >> $GITHUB_ENV
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH" >> $GITHUB_ENV
-
-    - name: Install dependencies
-      run: |
-        pip install --upgrade pip
-        pip install -e .
-
-    - name: Test mpi notebooks
-      run : |
-        # Currently not tested due to issue #859
-        # ipcluster start --profile=mpi -n 4 --daemon
-        # py.test --nbval examples/mpi
-        # ipcluster stop --profile=mpi
-
-    - name: Test seismic examples
-      run: |
-        mpirun -n 4 pytest examples/seismic/tti/tti_example.py
-        mpirun -n 4 pytest examples/seismic/elastic/elastic_example.py
-        mpirun -n 4 pytest examples/seismic/viscoacoustic/viscoacoustic_example.py
-        mpirun -n 4 pytest examples/seismic/viscoelastic/viscoelastic_example.py
-
-    - name: Test fwi examples with mpi
-      run: |
-        mpirun -n 4 python examples/seismic/inversion/fwi.py
diff --git a/.github/workflows/examples.yml b/.github/workflows/examples.yml
deleted file mode 100644
index cc9e0a24e5..0000000000
--- a/.github/workflows/examples.yml
+++ /dev/null
@@ -1,89 +0,0 @@
-name: Examples
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  tutorials:
-    name: Examples with conda install
-    runs-on: ubuntu-latest
-
-    defaults:
-      # Default for conda env
-      run:
-        shell: bash -l {0}
-
-    env:
-      DEVITO_ARCH: gcc
-      DEVITO_LANGUAGE: "openmp"
-      PYTHON_VERSION: "3.7"
-
-    strategy:
-      # Prevent all build to stop if a single one fails
-      fail-fast: false
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v2
-
-    - name: Setup conda
-      uses: conda-incubator/setup-miniconda@v2
-      with:
-       activate-environment: devito
-       environment-file: environment-dev.yml
-       auto-activate-base: false
-
-    - name: Install dependencies
-      run: |
-        pip install -e .
-        pip install matplotlib
-
-    - name: Tests in examples
-      run: py.test --cov --cov-config=.coveragerc --cov-report=xml examples/
-
-    - name: Seismic acoustic examples
-      run: |
-        python examples/seismic/acoustic/acoustic_example.py --full
-        python examples/seismic/acoustic/acoustic_example.py --full --checkpointing
-        python examples/seismic/acoustic/acoustic_example.py --constant --full
-        python examples/seismic/acoustic/acoustic_example.py --fs
-        python examples/seismic/inversion/fwi.py
-        python examples/seismic/self_adjoint/example_iso.py
-        python examples/seismic/viscoacoustic/viscoacoustic_example.py
-        python examples/seismic/viscoacoustic/viscoacoustic_example.py -k ren
-        python examples/seismic/viscoacoustic/viscoacoustic_example.py -k deng_mcmechan
-
-    - name: Seismic tti examples
-      run: |
-        python examples/seismic/tti/tti_example.py -a basic
-        python examples/seismic/tti/tti_example.py -a basic --noazimuth
-        python examples/seismic/tti/tti_example.py -k staggered
-        python examples/seismic/tti/tti_example.py --full -so 12
-
-    - name: Seismic elastic examples
-      run: |
-        python examples/seismic/elastic/elastic_example.py
-        python examples/seismic/viscoelastic/viscoelastic_example.py
-
-    - name: Linear algebra example
-      run: |
-        python examples/misc/linalg.py mat-vec mat-mat mat-mat-sum transpose-mat-vec
-        python examples/misc/linalg.py mat-vec -o mat-mat -o mat-mat-sum -o transpose-mat-vec -o
-
-    - name: CFD examples
-      run: |
-        python examples/cfd/example_diffusion.py
-
-    - name: Upload coverage to Codecov
-      if: matrix.name != 'pytest-docker-py36-gcc-omp'
-      uses: codecov/codecov-action@v1.0.6
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }}
-        name: ${{ matrix.name }}
diff --git a/.github/workflows/flake8.yml b/.github/workflows/flake8.yml
deleted file mode 100644
index 72e7805a93..0000000000
--- a/.github/workflows/flake8.yml
+++ /dev/null
@@ -1,30 +0,0 @@
-name: Flake8
-
-on:
-   # Trigger the workflow on push or pull request,
-   # but only for the master branch
-   push:
-     branches:
-       - master
-   pull_request:
-     branches:
-       - master
-
-jobs:
-  flake8:
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v1
-    - name: Set up Python 3.7
-      uses: actions/setup-python@v1
-      with:
-        python-version: 3.7
-    - name: Install dependencies
-      run: |
-        python -m pip install --upgrade pip
-        pip install flake8
-    - name: Lint with flake8
-      run: |
-        flake8 --builtins=ArgumentError .
diff --git a/.github/workflows/pytest-core-mpi.yml b/.github/workflows/pytest-core-mpi.yml
deleted file mode 100644
index 202b9f9d19..0000000000
--- a/.github/workflows/pytest-core-mpi.yml
+++ /dev/null
@@ -1,43 +0,0 @@
-name: CI-mpi
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  build:
-    name: pytest-mpi
-    runs-on: ubuntu-20.04
-
-    env:
-      DEVITO_LANGUAGE: "openmp"
-      DEVITO_ARCH: "gcc-9"
-      CC: "gcc-9"
-      CXX: "g++-9"
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v2
-
-    - name: Install dependencies
-      run: |
-        sudo apt-get update && sudo apt install mpich -y
-        pip3 install --upgrade pip
-        pip3 install -r requirements-mpi.txt
-        pip3 install -e .[extras]
-
-    - name: Test with pytest
-      run: |
-        python3 -m pytest --cov --cov-config=.coveragerc --cov-report=xml -m parallel tests/
-
-    - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v1.0.15
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }}
-        name: pytest-mpi
diff --git a/.github/workflows/pytest-gpu.yml b/.github/workflows/pytest-gpu.yml
deleted file mode 100644
index 0c41ee49d5..0000000000
--- a/.github/workflows/pytest-gpu.yml
+++ /dev/null
@@ -1,119 +0,0 @@
-# Runner information:
-# OpenACC on NVidia runs on `sarlaac`
-# OpenMP on NVidia runs on `kimogila`
-
-name: CI-gpu
-
-env:
-  OUTPUT_PATH: ${{ github.workspace }}
-  RESOURCE_GROUP: CI-gpu
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-  # Push-button activation
-  workflow_dispatch:
-    inputs:
-      tags:
-        description: 'Run GPU tests'
-
-jobs:
-
-  build:
-    name: ${{ matrix.name }}
-    runs-on: ${{ matrix.tags }}
-
-    env:
-      DEVITO_ARCH: ${{ matrix.arch }}
-      DEVITO_PLATFORM: ${{ matrix.platform }}
-      DEVITO_LANGUAGE: ${{ matrix.language }}
-      OMPI_CC: ${{ matrix.arch }}
-
-    strategy:
-      # Prevent all builds from terminating if one fails
-      fail-fast: false
-
-      matrix:
-        name: [
-          # NOTE: We can re-instate this as a 'failing' build
-          # as soon as the hardware is ready
-          pytest-gpu-omp,
-          pytest-gpu-acc
-          # pytest-gpu-aomp
-        ]
-        include:
-        - name: pytest-gpu-omp
-          test_file: "tests/test_gpu_openmp.py"
-          env_file: "devito-ci-nvidia-openmp.env"
-          test_drive_cmd: "nvidia-smi"
-          arch: "clang"
-          platform: "nvidiaX"
-          language: "openmp"
-          tags: ["self-hosted", "gpu", "openmp"]
-
-        - name: pytest-gpu-acc
-          test_file: "tests/test_gpu_openacc.py"
-          env_file: "devito-ci-nvidia-openacc.env"
-          test_drive_cmd: "nvidia-smi"
-          arch: "nvcc"
-          platform: "nvidiaX"
-          language: "openacc"
-          tags: ["self-hosted", "gpu", "openacc"]
-
-        # - name: pytest-gpu-aomp
-        #   test_file: "tests_gpu_aomp.py"
-        #   env_file: "devito-ci-amd-openmp.py"
-        #   test_drive_cmd: "TODO"
-        #   arch: "aomp"
-        #   platform: "amdgpuX"
-        #   language: "openmp"
-        #   tags: ["self-hosted", "gpu", "aomp"]
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v1
-
-    - name: Set environment
-      run: |
-        source $HOME/${{ matrix.env_file }}
-        echo "PATH=$PATH" >> $GITHUB_ENV
-        echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH" >> $GITHUB_ENV
-
-    - name: Install dependencies
-      run: |
-        pip3 install --upgrade pip
-        pip3 install -e .[extras]
-
-    - name: Test with pytest
-      run: |
-        ${{ matrix.test_drive_cmd }}
-        pytest --cov --cov-config=.coveragerc --cov-report=xml tests/test_adjoint.py tests/test_gpu_common.py
-        pytest --cov --cov-config=.coveragerc --cov-report=xml ${{ matrix.test_file }}
-
-    - name: Test examples
-      run: |
-        pytest examples/seismic/acoustic/acoustic_example.py
-        pytest examples/seismic/elastic/elastic_example.py
-        pytest examples/seismic/tti/tti_example.py
-        pytest examples/seismic/viscoacoustic/viscoacoustic_example.py
-        pytest examples/seismic/viscoelastic/viscoelastic_example.py
-
-    - name: Test examples with MPI
-      run: |
-        DEVITO_MPI=1 mpirun -n 2 pytest examples/seismic/acoustic/acoustic_example.py
-        DEVITO_MPI=1 mpirun -n 2 pytest examples/seismic/elastic/elastic_example.py
-        DEVITO_MPI=1 mpirun -n 2 pytest examples/seismic/tti/tti_example.py
-        DEVITO_MPI=1 mpirun -n 2 pytest examples/seismic/viscoacoustic/viscoacoustic_example.py
-        DEVITO_MPI=1 mpirun -n 2 pytest examples/seismic/viscoelastic/viscoelastic_example.py
-
-    - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v1.0.6
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }}
-        name: ${{ matrix.name }}
diff --git a/.github/workflows/pythonpublish.yml b/.github/workflows/pythonpublish.yml
deleted file mode 100644
index 6ae0f32795..0000000000
--- a/.github/workflows/pythonpublish.yml
+++ /dev/null
@@ -1,26 +0,0 @@
-name: Upload to PyPI
-
-on:
-  release:
-    types: [published]
-
-jobs:
-  deploy:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v1
-    - name: Set up Python
-      uses: actions/setup-python@v1
-      with:
-        python-version: '3.x'
-    - name: Install dependencies
-      run: |
-        python -m pip install --upgrade pip
-        pip install setuptools wheel twine
-    - name: Build and publish
-      env:
-        TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
-        TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
-      run: |
-        python setup.py sdist bdist_wheel
-        twine upload dist/*
diff --git a/.github/workflows/release-notes.yml b/.github/workflows/release-notes.yml
deleted file mode 100644
index 2c30bcdb18..0000000000
--- a/.github/workflows/release-notes.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-name: Release Drafter
-
-on:
-  push:
-    # branches to consider in the event; optional, defaults to all
-    branches:
-      - master
-
-jobs:
-  update_release_draft:
-    runs-on: ubuntu-latest
-    steps:
-      # Drafts your next Release notes as Pull Requests are merged into "master"
-      - uses: release-drafter/release-drafter@v5
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/tutorials.yml b/.github/workflows/tutorials.yml
deleted file mode 100644
index 721be93ab7..0000000000
--- a/.github/workflows/tutorials.yml
+++ /dev/null
@@ -1,139 +0,0 @@
-name: Jupyter Notebooks
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  tutorials:
-    name: ${{ matrix.name }}
-    runs-on: ${{ matrix.os }}
-
-    env:
-      DEVITO_ARCH: "${{ matrix.compiler }}"
-      DEVITO_LANGUAGE: ${{ matrix.language }}
-      PYTHON_VERSION: "3.7"
-
-    strategy:
-      # Prevent all build to stop if a single one fails
-      fail-fast: false
-      matrix:
-        name: [
-          tutos-ubuntu-gcc-py37,
-          tutos-osx-gcc-py37,
-          tutos-osx-clang-py37,
-          tutos-docker-gcc-py36
-          ]
-
-        include:
-          - name: tutos-ubuntu-gcc-py37
-            os: ubuntu-16.04
-            compiler: gcc
-            language: "openmp"
-
-          - name: tutos-osx-gcc-py37
-            os: macos-latest
-            compiler: gcc-9
-            language: "openmp"
-
-          - name: tutos-osx-clang-py37
-            os: macos-latest
-            compiler: clang
-            language: "C"
-
-          - name: tutos-docker-gcc-py36
-            os: ubuntu-latest
-            compiler: gcc
-            language: "openmp"
-
-    steps:
-    - name: Checkout devito
-      uses: actions/checkout@v1
-
-    - name: Set up Python 3.7
-      if: matrix.name != 'tutos-docker-gcc-py36'
-      uses: actions/setup-python@v1
-      with:
-        python-version: 3.7
-
-    - name: Install compilers for OSX
-      if: runner.os == 'macOS'
-      run: |
-        if [ "${{ matrix.compiler }}" = "gcc-9" ]; then
-          brew install gcc@9
-        else
-          sudo xcode-select -s /Applications/Xcode_12.2.app/Contents/Developer
-        fi
-
-    - name: Build docker image
-      if: matrix.name == 'tutos-docker-gcc-py36'
-      run: |
-          docker build . --file docker/Dockerfile --tag devito_img
-
-    - name: Set run prefix
-      run: |
-          if [ "${{ matrix.name }}" == 'tutos-docker-gcc-py36' ]; then
-              echo "::set-output name=RUN_CMD::docker run --rm --name testrun devito_img"
-          else
-              echo "::set-output name=RUN_CMD::"
-          fi
-      id: set-run
-
-    - name: Install dependencies
-      if: matrix.name != 'tutos-docker-gcc-py36'
-      run: |
-        python -m pip install --upgrade pip
-        pip install -e .
-        pip install matplotlib blosc
-
-    - name: Seismic notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:seis_coverage.xml -k 'not dask' examples/seismic/tutorials/  # Horrible, but we're still at a loss
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:acc_coverage.xml examples/seismic/acoustic/accuracy.ipynb
-
-    - name: Dask notebooks
-      if: runner.os != 'macOS'
-      run: |
-          ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:seis_coverage.xml examples/seismic/tutorials/*dask*.ipynb
-
-    - name: Self-adjoint notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:sa_coverage.xml examples/seismic/self_adjoint/
-
-    - name: CFD notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:cfd_coverage.xml examples/cfd
-
-    - name: User api notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:api_coverage.xml examples/userapi
-
-    - name: Compiler notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:comp_coverage.xml examples/compiler
-        
-    - name: Finance notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:comp_coverage.xml examples/finance
-
-    - name: Performance notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:comp_coverage.xml examples/performance
-
-    - name: ABC Notebooks
-      run: |
-        ${{ steps.set-run.outputs.RUN_CMD }} py.test --nbval --cov . --cov-config=.coveragerc --cov-report=xml:comp_coverage.xml examples/seismic/abc_methods
-
-    - name: Upload coverage to Codecov
-      if: matrix.name != 'tutos-docker-gcc-py36'
-      uses: codecov/codecov-action@v1.0.6
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }}
-        name: ${{ matrix.name }}
-        file: ./*_coverage.xml
diff --git a/devito/operator/operator.py b/devito/operator/operator.py
index 3132be38a3..3155464a10 100644
--- a/devito/operator/operator.py
+++ b/devito/operator/operator.py
@@ -478,7 +478,7 @@ def _prepare_arguments(self, **kwargs):
             p._arg_check(args, self._dspace[p])
         for d in self.dimensions:
             if d.is_Derived:
-                d._arg_check(args, self._dspace[p])
+                d._arg_check(args, self._dspace[d]) # BUG?
 
         # Turn arguments into a format suitable for the generated code
         # E.g., instead of NumPy arrays for Functions, the generated code expects
diff --git a/devito/types/dense.py b/devito/types/dense.py
index affa8cebe6..45b0873a53 100644
--- a/devito/types/dense.py
+++ b/devito/types/dense.py
@@ -860,7 +860,11 @@ def _arg_check(self, args, intervals):
             warning("Data type %s of runtime value `%s` does not match the "
                     "Function data type %s" % (key.dtype, self.name, self.dtype))
         for i, s in zip(self.dimensions, key.shape):
-            i._arg_check(args, s, intervals[i])
+            if i not in intervals and i.is_Sub:
+                interval = intervals[i.parent]
+            else: 
+                interval = intervals[i]
+            i._arg_check(args, s, interval)
 
     def _arg_as_ctype(self, args, alias=None):
         key = alias or self
diff --git a/devito/types/dimension.py b/devito/types/dimension.py
index 06e6a11869..6bfe78c5ac 100644
--- a/devito/types/dimension.py
+++ b/devito/types/dimension.py
@@ -11,6 +11,8 @@
 from devito.types.args import ArgProvider
 from devito.types.basic import Symbol, DataSymbol, Scalar
 
+import inspect
+
 __all__ = ['Dimension', 'SpaceDimension', 'TimeDimension', 'DefaultDimension',
            'CustomDimension', 'SteppingDimension', 'SubDimension', 'ConditionalDimension',
            'dimensions', 'ModuloDimension', 'IncrDimension']
@@ -672,6 +674,20 @@ def _arg_values(self, args, interval, grid, **kwargs):
         ['symbolic_min', 'symbolic_max', 'thickness', 'local']
     _pickle_kwargs = []
 
+    def _arg_check(self, *args):
+        if len(args) == 2:
+            # Comes from Operator._prepare_arguments
+            dargs, interval = args
+        else:
+            # Comes from DiscreteFunction._arg_check
+            dargs, size, interval = args
+            if not interval.is_Null:
+                test0 = self._interval.subs(dargs).start + interval.lower < 0
+                test1 = self._interval.subs(dargs).end + interval.upper > size
+                if test0 or test1:
+                    raise ValueError(' OOB access\n')
+        return
+
 
 class ConditionalDimension(DerivedDimension):
 
diff --git a/tests/test_derivatives.py b/tests/test_derivatives.py
index 08feb3a07e..4963cb9545 100644
--- a/tests/test_derivatives.py
+++ b/tests/test_derivatives.py
@@ -3,7 +3,7 @@
 from sympy import simplify, diff, Float
 
 from devito import (Grid, Function, TimeFunction, Eq, Operator, NODE, cos, sin,
-                    ConditionalDimension, left, right, centered, div, grad)
+                    SubDimension, ConditionalDimension, left, right, centered, div, grad)
 from devito.finite_differences import Derivative, Differentiable
 from devito.finite_differences.differentiable import EvalDerivative
 from devito.symbolics import indexify, retrieve_indexed
@@ -488,3 +488,98 @@ def test_shifted_grad(self, shift, ndim):
             x0 = (None if shift is None else d + shift[i] * d.spacing if
                   type(shift) is tuple else d + shift * d.spacing)
             assert gi == getattr(f, 'd%s' % d.name)(x0=x0).evaluate
+
+    @pytest.mark.parametrize('exprs, error,', [
+        ### Dimensions
+        
+        # # OOB access avoided by iteration space shrinking
+        (['Eq(so2.forward, so2.dx.dx.dx)'],None),
+        (['Eq(so2.forward, (so2+so0).dx2 )'],None),
+        (['Eq(so2.forward, so2.biharmonic(1/so0) )'],None),
+        (['Eq(tk0so0[t+1,x,y], tk0so0[t,x-1,y] + tk0so0[t,x+1,y] )'],None),
+        
+        ### SubDimensions (Thickness == 0)
+        
+        # Indices within the halo 
+        # (['Eq(so0[t+1,xm0,y], so0[t,xm0,y] + so0[t,xm0,y] )'],None), 
+        # (['Eq(so1[t+1,xm0,y], so1[t,xm0-1,y] + so1[t,xm0+1,y] )'],None), 
+        # (['Eq(so2[t+1,xm0,y], so2[t,xm0-2,y] + so2[t,xm0+2,y] )'],None),
+
+        # # OOB indices
+        # (['Eq(so0[t+1,xm0,y], so0[t,xm0-1,y] + so0[t,xm0+1,y] )'],ValueError),
+        # (['Eq(so1[t+1,xm0,y], so1[t,xm0-2,y] + so1[t,xm0+2,y] )'],ValueError), 
+        # (['Eq(so2[t+1,xm0,y], so2[t,xm0-3,y] + so2[t,xm0+3,y] )'],ValueError),
+        
+        (['Eq(tk0so2.forward, (tk0so2+tk0so0).dx2 )'],ValueError),
+        (['Eq(tk0so2.forward, tk0so2.dx.dx.dx.dx)'],ValueError),
+
+        ### SubDimensions (Thickness == 1)
+        
+        # # Indices within the halo + subdimension offset
+        # (['Eq(so0[t+1,xm1,y], so0[t,xm1-1,y] + so0[t,xm1+1,y] )'],None),
+        # (['Eq(so1[t+1,xm1,y], so1[t,xm1-2,y] + so1[t,xm1+2,y] )'],None),
+        # (['Eq(so2[t+1,xm1,y], so2[t,xm1-3,y] + so2[t,xm1+3,y] )'],None),
+
+        # (['Eq(so0[t+1,xl1,y], so0[t,xl1,y] + so0[t,xl1+99,y] )'],None),
+        # (['Eq(so1[t+1,xl1,y], so1[t,xl1-1,y] + so1[t,xl1+100,y] )'],None),
+        # (['Eq(so2[t+1,xl1,y], so2[t,xl1-2,y] + so2[t,xl1+101,y] )'],None),
+        
+        # (['Eq(so0[t+1,xr1,y], so0[t,xr1-99,y] + so0[t,xr1,y] )'],None),
+        # (['Eq(so1[t+1,xr1,y], so1[t,xr1-100,y] + so1[t,xr1+1,y] )'],None),
+        # (['Eq(so2[t+1,xr1,y], so2[t,xr1-101,y] + so2[t,xr1+2,y] )'],None),
+        
+        (['Eq(tk1so2.forward, tk1so2.dx.dx.dx.dx)'],None),
+        (['Eq(tk1so2.forward, (tk1so2+tk1so0).dx2 )'],None),
+        
+        # # OOB indices
+        # (['Eq(so0[t+1,xm1,y], so0[t,xm1-2,y] + so0[t,xm1+2,y] )'],ValueError),
+        # (['Eq(so1[t+1,xm1,y], so1[t,xm1-3,y] + so1[t,xm1+3,y] )'],ValueError),
+        # (['Eq(so2[t+1,xm1,y], so2[t,xm1-4,y] + so2[t,xm1+4,y] )'],ValueError),
+
+        # (['Eq(so0[t+1,xl1,y], so0[t,xl1-1,y] + so0[t,xl1+100,y] )'],ValueError),
+        # (['Eq(so1[t+1,xl1,y], so1[t,xl1-2,y] + so1[t,xl1+101,y] )'],ValueError),
+        # (['Eq(so2[t+1,xl1,y], so2[t,xl1-3,y] + so2[t,xl1+102,y] )'],ValueError),
+
+        # (['Eq(so0[t+1,xr1,y], so0[t,xr1-100,y] + so0[t,xr1+1,y] )'],ValueError),
+        # (['Eq(so1[t+1,xr1,y], so1[t,xr1-101,y] + so1[t,xr1+2,y] )'],ValueError),
+        # (['Eq(so2[t+1,xr1,y], so2[t,xr1-102,y] + so2[t,xr1+3,y] )'],ValueError),
+        ])
+    def test_oobs(self, exprs, error):
+        
+        grid = Grid(tuple([100]*2))
+        x , y = grid.dimensions
+        t = grid.stepping_dim
+        
+        xm0 = SubDimension.middle(name='xm0', parent=x, thickness_left=0, thickness_right=0)
+        xm1 = SubDimension.middle(name='xm1', parent=x, thickness_left=1, thickness_right=1)
+
+        xl0 = SubDimension.left(name='xl0', parent=x, thickness=0)
+        xl1 = SubDimension.left(name='xl1', parent=x, thickness=1)
+
+        xr0 = SubDimension.right(name='xr0', parent=x, thickness=0)
+        xr1 = SubDimension.right(name='xr1', parent=x, thickness=1)
+        
+        so0 = TimeFunction(name="so0", grid=grid, time_order=1, space_order=0)
+        so1 = TimeFunction(name="so1", grid=grid, time_order=1, space_order=1)
+        so2 = TimeFunction(name="so2", grid=grid, time_order=1, space_order=2)
+
+        tk0so0 = TimeFunction(name="tk0so0", grid=grid, time_order=1, space_order=0, dimensions=(t,xm0,y))
+        tk0so1 = TimeFunction(name="tk0so1", grid=grid, time_order=1, space_order=1, dimensions=(t,xm0,y))
+        tk0so2 = TimeFunction(name="tk0so2", grid=grid, time_order=1, space_order=2, dimensions=(t,xm0,y))
+
+        tk1so0 = TimeFunction(name="tk1so0", grid=grid, time_order=1, space_order=0, dimensions=(t,xm1,y))
+        tk1so1 = TimeFunction(name="tk1so1", grid=grid, time_order=1, space_order=1, dimensions=(t,xm1,y))
+        tk1so2 = TimeFunction(name="tk1so2", grid=grid, time_order=1, space_order=2, dimensions=(t,xm1,y))
+
+        # List comprehension would need explicit locals/globals mappings to eval
+        for i, e in enumerate(list(exprs)):
+            exprs[i] = eval(e)
+        try:
+            op = Operator(exprs)
+            op.apply(time_M=6)
+        except Exception as e:
+            if error is None or not isinstance(e, error):
+                assert False, "Not expected: %s %s" % (type(e),e)
+        else:
+            if error is not None:
+                assert False, "Should raise an %s exception" % error