[STATEMENT]
lemma "g = Let (A \<or> B)"
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. g = Let (A \<or> B)
[PROOF STEP]
nitpick [card = 1, expect = none]
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. g = Let (A \<or> B)
[PROOF STEP]
nitpick [card = 12, expect = genuine]
[PROOF STATE]
proof (prove)
goal (1 subgoal):
 1. g = Let (A \<or> B)
[PROOF STEP]
oops