[perl6/specs] bbebb3: remove rule

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/perl6/specs
  Commit: bbebb3763a3c733ce741bd9da5f3da0792420ed2
      
https://github.com/perl6/specs/commit/bbebb3763a3c733ce741bd9da5f3da0792420ed2
  Author: Larry Wall <la...@wall.org>
  Date:   2013-12-27 (Fri, 27 Dec 2013)

  Changed paths:
    M S05-regex.pod

  Log Message:
  -----------
  remove <prior> rule

This is a low-gain feature that penalizes everyone.