Obviously the antonym of inverse cant be verse since the English would language never rely on context to establish the meaning of a word.

According to the magnanimous synonym.com, it depends on the context, so it could either be direct or reverse.

When your “on the command line” or “in the shell” why is that no standard help operator? The lack of standardization can become really annoying

Some need –help, some like ? other a simple -h will do.

Granted, it’s not something that you run into everyday, but when it’s late in the evening, nothing can be more annoying when you just need to double check an operator on some obscure litte program.

Turns out yes, the direct antonym for infallible just happens to be  fallible – not a coincidence I’m sure.