-val level1_pattern_lexer: (string * string) Token.glexer
-val level2_ast_lexer: (string * string) Token.glexer
-val level2_meta_lexer: (string * string) Token.glexer
+val level1_pattern_lexer: unit -> (string * string) Token.glexer
+val level2_ast_lexer: unit -> (string * string) Token.glexer
+val level2_meta_lexer: unit -> (string * string) Token.glexer