2. Conveying Modified Versions.

  If you modify a copy of the Library, and, in your modifications, a
facility refers to a function or data to be supplied by an Application
that uses the facility (other than as an argument passed when the
facility is invoked), then you may convey a copy of the modified
version:

   a) under this License, provided that you make a good faith effort to

pkg regexp/syntax, const ErrMissingBracket = "missing closing ]"
pkg regexp/syntax, const ErrMissingParen = "missing closing )"
pkg regexp/syntax, const ErrMissingRepeatArgument = "missing argument to repetition operator"
pkg regexp/syntax, const ErrTrailingBackslash = "trailing backslash at end of expression"
pkg regexp/syntax, const ErrUnexpectedParen = "unexpected )"