val assume : string -> Cic.term -> ProofEngineTypes.tactic
val suppose : Cic.term -> string -> ProofEngineTypes.tactic
val by_term_we_proved : Cic.term -> Cic.term -> string -> ProofEngineTypes.tactic
val bydone : Cic.term -> ProofEngineTypes.tactic
val we_need_to_prove : Cic.term -> string -> ProofEngineTypes.tactic