make: "cond1.mk" line 80: warning: extra else
make: "cond1.mk" line 90: warning: extra else
2 is  prime
A='other' B='unknown' C='clever' o='no,no'
Passed:
 var
 ("var")
 (var != var)
 var != var
 !((var != var) && defined(name))
 var == quoted

1 is not prime
2 is  prime
3 is  prime
4 is not prime
5 is  prime

make: String comparison operator must be either == or !=
make: Bad conditional expression '"0" > 0' in '"0" > 0?OK:No'

OK
exit status 0