syn region factorSymbols start=/\<SYMBOLS:\>/ end=/;/
syn region factorConstructor2 start=/\<CONSTRUCTOR:\?/ end=/;/
syn region factorIntersection start=/\<INTERSECTION:\>/ end=/\<;\>/
-syn region factorTuple start=/\<TUPLE:\>/ end=/\<;\>/
+syn region factorTuple start=/\<\(TUPLE\|BUILTIN\):\>/ end=/\<;\>/
syn region factorError start=/\<ERROR:\>/ end=/\<;\>/
syn region factorUnion start=/\<UNION:\>/ end=/\<;\>/
syn region factorStruct start=/\<\(UNION-STRUCT:\|STRUCT:\)\>/ end=/\<;\>/
syn region factorSymbols start=/\<SYMBOLS:\>/ end=/;/
syn region factorConstructor2 start=/\<CONSTRUCTOR:\?/ end=/;/
syn region factorIntersection start=/\<INTERSECTION:\>/ end=/\<;\>/
-syn region factorTuple start=/\<TUPLE:\>/ end=/\<;\>/
+syn region factorTuple start=/\<\(TUPLE\|BUILTIN\):\>/ end=/\<;\>/
syn region factorError start=/\<ERROR:\>/ end=/\<;\>/
syn region factorUnion start=/\<UNION:\>/ end=/\<;\>/
syn region factorStruct start=/\<\(UNION-STRUCT:\|STRUCT:\)\>/ end=/\<;\>/