From 3935eb0d704fedda9cf5b48a358af49e9bdd2114 Mon Sep 17 00:00:00 2001
From: Will Robertson <wspr81@gmail.com>
Date: Thu, 17 Jan 2019 12:44:59 +1030
Subject: [PATCH] improve message

it's a bit confusing the variations on messages we have! not rationalising now to keep diffs under control
---
 l3kernel/l3basics.dtx                  |  4 ++--
 l3kernel/testfiles/m3chk001.luatex.tlg | 24 ++++++++++++------------
 l3kernel/testfiles/m3chk001.tlg        | 24 ++++++++++++------------
 l3kernel/testfiles/m3chk004.luatex.tlg | 24 ++++++++++++------------
 l3kernel/testfiles/m3chk004.tlg        | 24 ++++++++++++------------
 l3kernel/testfiles/m3chk005.luatex.tlg | 12 ++++++------
 l3kernel/testfiles/m3chk005.tlg        | 12 ++++++------
 7 files changed, 62 insertions(+), 62 deletions(-)

diff --git a/l3kernel/l3basics.dtx b/l3kernel/l3basics.dtx
index 4e694351d7..b83e2ac7ca 100644
--- a/l3kernel/l3basics.dtx
+++ b/l3kernel/l3basics.dtx
@@ -1775,9 +1775,9 @@
             \cs_if_exist:NTF ##1
               { ##2 }
               {
-                ##3
                 \__kernel_msg_expandable_error:nnn
-                  { kernel } { non-declared-variable } { ##1 }
+                  { kernel } { variable-not-defined } { ##1 }
+                ##3
               }
           }
         \cs_set:Npn \__kernel_chk_exp_var_exist:NT ##1 ##2
diff --git a/l3kernel/testfiles/m3chk001.luatex.tlg b/l3kernel/testfiles/m3chk001.luatex.tlg
index 4d0fbdf78c..5012e77ca2 100644
--- a/l3kernel/testfiles/m3chk001.luatex.tlg
+++ b/l3kernel/testfiles/m3chk001.luatex.tlg
@@ -35,7 +35,7 @@ TEST 2: Use variables (undefined)
 CS
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_bbb:  undefined or invalid.
+                Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -53,7 +53,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_bbb:  undefined or invalid.
+                Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -64,7 +64,7 @@ and I'll forget about whatever was undefined.
 TL
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_tl  has not been declared \msg_line_context: 
+                Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -82,7 +82,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_tl  has not been declared \msg_line_context: 
+                Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -93,7 +93,7 @@ and I'll forget about whatever was undefined.
 STR
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_str  has not been declared \msg_line_context:
+                Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -111,7 +111,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_str  has not been declared \msg_line_context:
+                Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -137,7 +137,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_int  has not been declared \msg_line_context:
+                Variable \l_B_int  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -163,7 +163,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_dim  has not been declared \msg_line_context:
+                Variable \l_B_dim  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -189,7 +189,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_skip  has not been declared \msg_line_context
+                Variable \l_B_skip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -215,7 +215,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_muskip  has not been declared \msg_line_conte
+                Variable \l_B_muskip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -350,7 +350,7 @@ and I'll forget about whatever was undefined.
 FP
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_fp  has not been declared \msg_line_context: 
+                Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -360,7 +360,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_fp  has not been declared \msg_line_context: 
+                Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
diff --git a/l3kernel/testfiles/m3chk001.tlg b/l3kernel/testfiles/m3chk001.tlg
index 26ad34e9e3..f3c2681581 100644
--- a/l3kernel/testfiles/m3chk001.tlg
+++ b/l3kernel/testfiles/m3chk001.tlg
@@ -35,7 +35,7 @@ TEST 2: Use variables (undefined)
 CS
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_bbb:  undefined or invalid.
+                           Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -53,7 +53,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_bbb:  undefined or invalid.
+                           Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -64,7 +64,7 @@ and I'll forget about whatever was undefined.
 TL
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_tl  has not been declared \msg_...
+                           Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -82,7 +82,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_tl  has not been declared \msg_...
+                           Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -93,7 +93,7 @@ and I'll forget about whatever was undefined.
 STR
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_str  has not been declared \msg...
+                           Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -111,7 +111,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_str  has not been declared \msg...
+                           Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -137,7 +137,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_int  has not been declared \msg...
+                           Variable \l_B_int  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -163,7 +163,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_dim  has not been declared \msg...
+                           Variable \l_B_dim  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -189,7 +189,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_skip  has not been declared \ms...
+                           Variable \l_B_skip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -215,7 +215,7 @@ I'm forgetting what you said and using zero instead.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_muskip  has not been declared \...
+                           Variable \l_B_muskip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -350,7 +350,7 @@ and I'll forget about whatever was undefined.
 FP
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_fp  has not been declared \msg_...
+                           Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -360,7 +360,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_fp  has not been declared \msg_...
+                           Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
diff --git a/l3kernel/testfiles/m3chk004.luatex.tlg b/l3kernel/testfiles/m3chk004.luatex.tlg
index 124fe906b9..831d684351 100644
--- a/l3kernel/testfiles/m3chk004.luatex.tlg
+++ b/l3kernel/testfiles/m3chk004.luatex.tlg
@@ -50,7 +50,7 @@ TEST 2: Use variables (undefined)
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_bbb:  undefined or invalid.
+                Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -69,7 +69,7 @@ CS:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_bbb:  undefined or invalid.
+                Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -80,7 +80,7 @@ CS:\cs_bbb:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_tl  has not been declared \msg_line_context: 
+                Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -99,7 +99,7 @@ TL:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_tl  has not been declared \msg_line_context: 
+                Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -110,7 +110,7 @@ TL:\l_B_tl
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_str  has not been declared \msg_line_context:
+                Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -129,7 +129,7 @@ STR:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_str  has not been declared \msg_line_context:
+                Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -165,7 +165,7 @@ INT:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_int  has not been declared \msg_line_context:
+                Variable \l_B_int  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -201,7 +201,7 @@ DIM:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_dim  has not been declared \msg_line_context:
+                Variable \l_B_dim  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -237,7 +237,7 @@ SKIP:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_skip  has not been declared \msg_line_context
+                Variable \l_B_skip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -273,7 +273,7 @@ MUSKIP:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_muskip  has not been declared \msg_line_conte
+                Variable \l_B_muskip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -328,7 +328,7 @@ CLIST:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_fp  has not been declared \msg_line_context: 
+                Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -339,7 +339,7 @@ FP:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                The variable \l_B_fp  has not been declared \msg_line_context: 
+                Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
diff --git a/l3kernel/testfiles/m3chk004.tlg b/l3kernel/testfiles/m3chk004.tlg
index 02658eddef..f74e775762 100644
--- a/l3kernel/testfiles/m3chk004.tlg
+++ b/l3kernel/testfiles/m3chk004.tlg
@@ -50,7 +50,7 @@ TEST 2: Use variables (undefined)
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_bbb:  undefined or invalid.
+                           Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -69,7 +69,7 @@ CS:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_bbb:  undefined or invalid.
+                           Control sequence \cs_bbb:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -80,7 +80,7 @@ CS:\cs_bbb:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_tl  has not been declared \msg_...
+                           Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -99,7 +99,7 @@ TL:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_tl  has not been declared \msg_...
+                           Variable \l_B_tl  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -110,7 +110,7 @@ TL:\l_B_tl
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_str  has not been declared \msg...
+                           Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -129,7 +129,7 @@ STR:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_str  has not been declared \msg...
+                           Variable \l_B_str  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -165,7 +165,7 @@ INT:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_int  has not been declared \msg...
+                           Variable \l_B_int  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -201,7 +201,7 @@ DIM:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_dim  has not been declared \msg...
+                           Variable \l_B_dim  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -237,7 +237,7 @@ SKIP:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_skip  has not been declared \ms...
+                           Variable \l_B_skip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -273,7 +273,7 @@ MUSKIP:0
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_muskip  has not been declared \...
+                           Variable \l_B_muskip  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -328,7 +328,7 @@ CLIST:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_fp  has not been declared \msg_...
+                           Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -339,7 +339,7 @@ FP:
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           The variable \l_B_fp  has not been declared \msg_...
+                           Variable \l_B_fp  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
diff --git a/l3kernel/testfiles/m3chk005.luatex.tlg b/l3kernel/testfiles/m3chk005.luatex.tlg
index 6425f57ec8..9c4eb6f6b1 100644
--- a/l3kernel/testfiles/m3chk005.luatex.tlg
+++ b/l3kernel/testfiles/m3chk005.luatex.tlg
@@ -6,7 +6,7 @@ TEST 1: CS undefined and relax
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_aaa:  undefined or invalid.
+                Control sequence \cs_aaa:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -24,7 +24,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \scan_stop:  undefined or invalid.
+                Control sequence \scan_stop:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -35,7 +35,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \relax  undefined or invalid.
+                Control sequence \relax  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -46,7 +46,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \cs_aaa:  undefined or invalid.
+                Control sequence \cs_aaa:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -57,7 +57,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \scan_stop:  undefined or invalid.
+                Control sequence \scan_stop:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -68,7 +68,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                Control sequence \relax  undefined or invalid.
+                Control sequence \relax  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
diff --git a/l3kernel/testfiles/m3chk005.tlg b/l3kernel/testfiles/m3chk005.tlg
index 5fb72e7290..d97fbb6664 100644
--- a/l3kernel/testfiles/m3chk005.tlg
+++ b/l3kernel/testfiles/m3chk005.tlg
@@ -6,7 +6,7 @@ TEST 1: CS undefined and relax
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_aaa:  undefined or invalid.
+                           Control sequence \cs_aaa:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -24,7 +24,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \scan_stop:  undefined or invalid.
+                           Control sequence \scan_stop:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -35,7 +35,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \relax  undefined or invalid.
+                           Control sequence \relax  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -46,7 +46,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \cs_aaa:  undefined or invalid.
+                           Control sequence \cs_aaa:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -57,7 +57,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \scan_stop:  undefined or invalid.
+                           Control sequence \scan_stop:  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have
@@ -68,7 +68,7 @@ and I'll forget about whatever was undefined.
 ============================================================
 ! Undefined control sequence.
 <argument> \LaTeX3 error: 
-                           Control sequence \relax  undefined or invalid.
+                           Control sequence \relax  undefined.
 l. ...  }
 The control sequence at the end of the top line
 of your error message was never \def'ed. If you have