class seqengine :Inherits#state ->object..end
method set_sequence : Wp.Conditions.sequence -> unitInitialize state with this sequence
method set_goal : Wp.Lang.F.pred -> unitAdds goal to state domain
method set_sequent : Wp.Conditions.sequent -> unitSet sequence and goal
method get_state : boolIf true, states are rendered when printing sequences.
method set_state : bool -> unitIf set to false, states rendering is deactivated.