ftnchek is a verifier for Fortran 77 programs, (much like the "lint" program used by C programmers). It is not designed to catch language syntax errors, that is the function of the compiler, (prior to using ftnchek, the user should verify that the program compiles correctly). It`s purpose is to assist the user in finding semantic errors. Namely, things that are legal in the Fortran 77 language, but appear suspicious in nature, and may lead to unintended results. For example, using a variable before it has been initialized, variables that are declared and never used, function calls with the wrong number of arguments, etc.