Declare that YYLSTYPE is not the default trivial datatype used by bison. (was causing compile errors in bison ver >= 2.7)
IEC 61131-3 Annex F Examples (informative)
This directory contains example code take from:
Annex F of Draft 2nd edition of the IEC 61131-3 standard (1998)
"PROGRAMMABLE CONTROLLERS - PROGRAMMING LANGUAGES"