fun alternate(bitstring, bitstring): bitstring.
fun push(bitstring, bitstring): bitstring.
const nil:bitstring.

equation forall y:bitstring; alternate(nil,y) = y;
	 forall x:bitstring, y:bitstring, z:bitstring; alternate(push(x,y),z) = push(x,alternate(z,y)) [convergent].

process 0