- The lexer, parser and BISON share one common error in the function definitions: Even though a definition like printTree() { // blah blah } compiles, it is not correct C. Normally, it should be rather void printTree( void ) { // blah blah } - The other error common to the lexer and parser is: The line saying sizeof( yylex ) which was there to mean "yylex's length", so should rather be strlen( yylex ) I think that's all S. Ali Tokmen http://ali.tokmen.com