Reciept to capture Reciepts of awaited Instructions

[andrewzhurov]

Inputs of an Instruction may be outputs of other Instructions. For such cases use of "await" is suggested.
As per the spec, usage of ZKProofs is not mandatory, leaving us with uncertainty in truthfulness of Reciepts.
The scenario of multiple Reciepts with different Results for the same Insruction may occur.
When there is an Instruction that depends on other Instructions, would it be of use to capture in it's Reciept the exact Receipts those dependency Instructions been resolved to?

It seems doing so would enhance provenance and allow for invalidation of dependent Reciepts when a Reciept they depend on downstream became known as untruthful.

On example of (2+2)*2, where (2+2) has been untruthfully computed as 5, making dependent (2+2)*2 = 5*2 = 10 calculation invalid.
*2 dependency on a particular result (Reciept) of (2+2) is captured in "awaited" field of its Reciept.

(data model is based on v0.2, some fields are ommited)

{"bafy...2+2":
 {"rsc": "<wasm module>",
  "op": "+",
  "inputs": [2, 2]},

 "bafy...2+2=5 Reciept":
 {"ran": {"/": "bafy...2+2 Invocation"},
  "out": {"ok": 5}},

 "bafy...(2+2)*2":
 {"rsc": "<wasm module>",
  "op": "*",
  "input": [{"await/ok": {"/": "bafy...2+2"}},
            2]},

 "bafy...(2+2)*2=10 Reciept":
 {"ran": {"/": "bafy...(2+2)*2 Invocation"},
  "out": {"ok": 10},
  "awaited": [{"input": {"/": "bafy...2+2"},
               "reciept": {"/": "bafy...2+2=5 Reciept"}}]}}

Then, having we learned that (2+2) = 5 is untruthful, it's possible to track and invalidate the dependent (2+2)*2 = 5*2 = 10 result.