gtk:check-version (major minor micro)

major -- an unsigned integer for the required major version
minor -- an unsigned integer for the required minor version
micro -- an unsigned integer for the required micro version

The nil value if the GTK library is compatible with the given version, or a string describing the version mismatch.

Checks that the GTK library in use is compatible with the given version. Compatibility is defined by two things: first the version of the running library is newer than the major.minor.micro version. Second the running library must be binary compatible with the major.minor.micro version (same major version).