(* Equality facts should not be accepted in hypotheses of <-> or <=>
   because they are going to generate C -> M = N *)

pred p/2.
fun f/1.
clauses
p:x,y & x = y <=> p:f(x),f(y).

free c. 

private free m.


(* Check if attacker can recover m*)
 
 query attacker:m.

(* processes *)

fun hostA/0.

process  
	 phase 1; in(c, =hostA); out(c, m)


(* EXPECTPV
Error: = fact not allowed here.
xtime: error in child process (status : 2)
END *)
