>>12Oh hai
thrD(a,b,c) := not(a=b=c)frE( a, b, c, d ) := not( thrD( a, b, c) or thrD(b,c,d) )
thrD(a,b,c) := not(a=b=c)
frE( a, b, c, d ) := not( thrD( a, b, c) or thrD(b,c,d) )