1163.lean:6:8-6:15: warning: declaration uses 'sorry' 1163.lean:11:8-11:15: warning: declaration uses 'sorry' 1163.lean:13:16-13:17: error: failed to synthesize instance OfNat Bool 0 1163.lean:15:8-15:15: warning: declaration uses 'sorry' 1163.lean:18:18-18:19: error: failed to synthesize instance OfNat Bool 0