Man pages matching name owl::directsemantics::writer::functionalsyntax in section 3pm:

OWL::DirectSemantics::Writer::FunctionalSyntax.3pm.en	debian 10 / libowl-directsemantics-perl
OWL::DirectSemantics::Writer::FunctionalSyntax.3pm.en	debian 12 / libowl-directsemantics-perl