Coq 8.6 and Software Foundations Fix

LibTactics.v

(*
The error while running `make` is:

File "./LibTactics.v", line 3238, characters 17-18:
Syntax error: ')' expected after [constr:lconstr] (in [tactic:tactic_arg]).

The fix to line 3238 is below.
*)

Ltac branch_tactic K N := (* Line 3237 *)
  match constr:((K,N)) with (* (K, N) -> ((K, N)) *)
  | (_,0) => fail 1
  | (0,_) => fail 1
  | (1,1) => idtac
  | (1,_) => left
  | (S ?K', S ?N') => right; branch_tactic K' N'
  end.