!!SuperPrime

!!SuperPrime is a language created by anonymous Esolangs user 100.1.142.136 in which the empty program is a prime checker.

The only command is a line of no characters.

An implementation in Pyth >2lPQ

Or, an alternate implementation in J: SP =: (0 0$0)"_`(1&p:@[)@.( ' '-:])

Call like:

input SP program

Example:

2 SP '' 1   2 SP '4' 3 SP '4' 4 SP '4' 4 SP '' 0