val we_need_to_prove :
Cic.term -> string option -> Cic.term option -> ProofEngineTypes.tactic
+val we_proceed_by_cases_on : Cic.term -> Cic.term -> ProofEngineTypes.tactic
+
val we_proceed_by_induction_on : Cic.term -> Cic.term -> ProofEngineTypes.tactic
val byinduction : Cic.term -> string -> ProofEngineTypes.tactic