diff --git a/mpact/sim/decoder/BinFormat.g4 b/mpact/sim/decoder/BinFormat.g4
index 41473ba..17d6480 100644
--- a/mpact/sim/decoder/BinFormat.g4
+++ b/mpact/sim/decoder/BinFormat.g4
@@ -129,7 +129,7 @@
 // An instruction group lists the encodings of a set of instructions that all
 // derive from the same format.
 instruction_group_def
-  : INSTRUCTION GROUP name=IDENT '[' number ']' ':' format=IDENT
+  : INSTRUCTION GROUP name=IDENT '[' number ']' ':' inst_format=IDENT
     '{' instruction_def_list '}' ';'?
   | INSTRUCTION GROUP name=IDENT '=' '{' group_name_list '}' ';'?
   ;
@@ -150,10 +150,10 @@
 
 range_assignment
   : IDENT '=' '[' gen_value (',' gen_value)* ']'
-  | '[' IDENT (',' IDENT)* ']' '=' '[' tuple (',' tuple)* ']'
+  | '[' IDENT (',' IDENT)* ']' '=' '[' value_list (',' value_list)* ']'
   ;
 
-tuple
+value_list
   : '{' gen_value (',' gen_value)* '}'
   ;
 
diff --git a/mpact/sim/decoder/InstructionSet.g4 b/mpact/sim/decoder/InstructionSet.g4
index 1c5951e..cefbc9a 100644
--- a/mpact/sim/decoder/InstructionSet.g4
+++ b/mpact/sim/decoder/InstructionSet.g4
@@ -351,10 +351,10 @@
 // Special rules for generator instruction descriptions.
 range_assignment
   : IDENT '=' '[' gen_value (',' gen_value)* ']'
-  | '[' IDENT (',' IDENT)* ']' '=' '[' tuple (',' tuple)* ']'
+  | '[' IDENT (',' IDENT)* ']' '=' '[' value_list (',' value_list)* ']'
   ;
 
-tuple
+value_list
   : '{' gen_value (',' gen_value)* '}'
   ;
 
diff --git a/mpact/sim/decoder/ProtoFormat.g4 b/mpact/sim/decoder/ProtoFormat.g4
index b8b7af9..05fbe30 100644
--- a/mpact/sim/decoder/ProtoFormat.g4
+++ b/mpact/sim/decoder/ProtoFormat.g4
@@ -49,10 +49,10 @@
 
 range_assignment
   : IDENT '=' '[' gen_value (',' gen_value)* ']'
-  | '[' IDENT (',' IDENT)* ']' '=' '[' tuple (',' tuple)* ']'
+  | '[' IDENT (',' IDENT)* ']' '=' '[' value_list (',' value_list)* ']'
   ;
 
-tuple
+value_list
   : '{' gen_value (',' gen_value)* '}'
   ;
 
diff --git a/mpact/sim/decoder/bin_format_visitor.cc b/mpact/sim/decoder/bin_format_visitor.cc
index 54ec8fd..8ab7ca5 100644
--- a/mpact/sim/decoder/bin_format_visitor.cc
+++ b/mpact/sim/decoder/bin_format_visitor.cc
@@ -948,7 +948,7 @@
   // format definitions.
   if (ctx->number() != nullptr) {
     int width = ConvertToInt(ctx->number());
-    std::string format_name = ctx->format->getText();
+    std::string format_name = ctx->inst_format->getText();
     auto iter = format_decl_map_.find(format_name);
     if (iter == format_decl_map_.end()) {
       error_listener_->semanticError(
@@ -1107,7 +1107,7 @@
       continue;
     }
     // It's a list of tuples with a structured binding assignment.
-    for (auto* tuple_ctx : assign_ctx->tuple()) {
+    for (auto* tuple_ctx : assign_ctx->value_list()) {
       if (tuple_ctx->gen_value().size() != range_info->range_names.size()) {
         // Clean up.
         for (auto* info : range_info_vec) delete info;
diff --git a/mpact/sim/decoder/instruction_set_contexts.h b/mpact/sim/decoder/instruction_set_contexts.h
index 3ae2e15..ca8d67d 100644
--- a/mpact/sim/decoder/instruction_set_contexts.h
+++ b/mpact/sim/decoder/instruction_set_contexts.h
@@ -56,7 +56,7 @@
 using GeneratorOpcodeSpecListCtx =
     InstructionSetParser::Generator_opcode_spec_listContext;
 using RangeAssignmentCtx = InstructionSetParser::Range_assignmentContext;
-using TupleCtx = InstructionSetParser::TupleContext;
+using ValueListCtx = InstructionSetParser::Value_listContext;
 using GenValueCtxt = InstructionSetParser::Gen_valueContext;
 
 }  // namespace instruction_set
diff --git a/mpact/sim/decoder/instruction_set_visitor.cc b/mpact/sim/decoder/instruction_set_visitor.cc
index 9b785cc..00172e4 100644
--- a/mpact/sim/decoder/instruction_set_visitor.cc
+++ b/mpact/sim/decoder/instruction_set_visitor.cc
@@ -1836,7 +1836,7 @@
       continue;
     }
     // It's a list of tuples with a structured binding assignment.
-    for (auto* tuple_ctx : assign_ctx->tuple()) {
+    for (auto* tuple_ctx : assign_ctx->value_list()) {
       if (tuple_ctx->gen_value().size() != range_info->range_names.size()) {
         for (auto* info : range_info_vec) delete info;
         return absl::InternalError(
diff --git a/mpact/sim/decoder/proto_format_visitor.cc b/mpact/sim/decoder/proto_format_visitor.cc
index c562e70..8dfb867 100644
--- a/mpact/sim/decoder/proto_format_visitor.cc
+++ b/mpact/sim/decoder/proto_format_visitor.cc
@@ -867,7 +867,7 @@
       continue;
     }
     // It's a list of tuples with a structured binding assignment.
-    for (auto* tuple_ctx : assign_ctx->tuple()) {
+    for (auto* tuple_ctx : assign_ctx->value_list()) {
       if (tuple_ctx->gen_value().size() != range_info->range_names.size()) {
         // Clean up.
         for (auto* info : range_info_vec) delete info;