let pp_goal_kind fmt = function
| PKProp
| PKPropLoop
| PKAFctOut
| PKAFctExit
| PKPre _ -> ()
| PKEstablished -> Format.pp_print_string fmt "Establishment of "
| PKPreserved -> Format.pp_print_string fmt "Preservation of "
| PKVarDecr -> Format.pp_print_string fmt "Decreasing of "
| PKVarPos -> Format.pp_print_string fmt "Positivity of "