[STATEMENT]
lemma roofed_gen_minus_web [simp]: "roofed_gen (\<Gamma> \<ominus> f) = roofed_gen \<Gamma>"
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. roofed_gen (\<Gamma> \<ominus> f) = roofed_gen \<Gamma>
[PROOF STEP]
by(simp add: fun_eq_iff roofed_def)