src/Pure/Syntax/README

Added filter_prems_tac

                              Pure/Syntax/


This directory contains the source files for Isabelle's syntax module,
which includes a lexer, parser, pretty printer and macro system. Note
that only the following structures are supposed to be exported:

  Pretty        (generic pretty printing module)
  Scan          (generic scanner toolbox)
  Source	(co-algebraic data sources)
  Symbol	(generalized characters)

  Syntax        (internal interface to the syntax module)
  BasicSyntax   (part of Syntax made pervasive)