problem ()
problem (
 rel: or 2 0 vars: a b       // or(!a !b)
 rel: or 2 0 vars: a   c
 rel: or 1 1 vars: a         // a
 rel: or 1 1 vars:   b
 rel: or 1 1 vars:     c
 )
problem (
 rel: or 2 1 vars: a b      //or(a !b): positives come first
 rel: or 2 1 vars: c b    //or(!b c): notice the order 
 )