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diff --git a/doc/0/grammar/peg.txt b/doc/0/grammar/peg.txt
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+# Standard PEG notation
+
+Stream       <- Unit ( Blank Unit )* !.
+
+
+Unit         <- Blank* Datum
+
+Blank        <- [\t-\r ] / Comment
+
+
+Datum        <- OneDatum ( JoinChar? OneDatum )*
+
+JoinChar     <- '.' / ':'
+
+
+Comment      <- ';' ( SkipUnit / SkipLine )
+
+SkipUnit     <- '~' Unit
+
+SkipLine     <- (!'\n' .)* '\n'?
+
+
+OneDatum     <- BareString / CladDatum
+
+
+BareString   <- SpecBareChar ( BareChar / JoinChar )*
+              / BareChar+
+
+SpecBareChar <- '+' / '-' / JoinChar / DIGIT
+
+BareChar     <- ALPHA / DIGIT
+              / '!' / '$' / '%' / '&' / '*' / '+' / '-' / '/'
+              / '<' / '=' / '>' / '?' / '^' / '_' / '~'
+
+
+CladDatum    <- PipeStr / QuoteStr / HashExpr / QuoteExpr / List
+
+PipeStr      <- '|' ( PipeStrChar / '\' StringEsc )* '|'
+QuoteStr     <- '"' ( QuotStrChar / '\' StringEsc )* '"'
+HashExpr     <- '#' HashExprs
+QuoteExpr    <- "'" Datum / '`' Datum / ',' Datum
+List         <- ParenList / SquareList / BraceList
+
+
+PipeStrChar  <- (![|\\] .)
+QuotStrChar  <- (!["\\] .)
+
+StringEsc    <- '\' / '|' / '"' / ( HTAB / SP )* LF ( HTAB / SP )*
+              / '0' / 'a' / 'b' / 't' / 'n' / 'v' / 'f' / 'r' / 'e'
+              / 'x' HexByte* ';'
+              / 'u' UnicodeSV ';'
+
+HexByte      <- HEXDIG HEXDIG
+UnicodeSV    <- HEXDIG+
+
+
+HashExprs    <- '!' [\t ]* HBangLine '\n'?
+              / '%' Label ( '%' / '=' Datum )
+              / '\' BareString / CladDatum
+              / Rune ( '\' BareString / CladDatum )?
+
+HBangLine    <- HBChars+ [\t ]* ( HBChars+ )?
+HBChars      <- (![\t\n ] .)
+Label        <- HEXDIG+
+Rune         <- ALPHA ( ALPHA / DIGIT )*
+
+
+ParenList    <- '(' Unit* ')'
+SquareList   <- '[' Unit* ']'
+BraceList    <- '{' Unit* '}'
+
+
+DIGIT        <- [0-9]
+ALPHA        <- [a-zA-Z]
+HEXDIG       <- [0-9a-fA-F]
+
+
+# Keep this in sync line-for-line with the ZBNF grammar for easy
+# comparison between the two.
+
+# This file is meant to be compatible with:
+# https://piumarta.com/software/peg
+
+# Due to a quirk in the peg tool this file is used with, the grammar
+# must not allow an empty stream.  Therefore, the Unit rule has its
+# Datum declared as mandatory rather than optional.
+
+
+# Local Variables:
+# eval: (flyspell-mode -1)
+# End: