doc/refintro.tex: Fix indexed-nonterminal argument abbreviation.
authorMark Wooding <mdw@distorted.org.uk>
Tue, 20 Aug 2019 11:24:32 +0000 (12:24 +0100)
committerMark Wooding <mdw@distorted.org.uk>
Tue, 20 Aug 2019 11:29:51 +0000 (12:29 +0100)
commit48c123c9d37880d48d415309b014325e5bc55162
tree8dc812fa12b4eeae3058708f2cb21cb045eb0e29
parentf736d657b15a29500c61c28644de6b558c08d912
doc/refintro.tex: Fix indexed-nonterminal argument abbreviation.

The thing with the unfinished ellipsis causes a very unpleasant effect
where dots at different heights are separated only by a comma.
Reluctantly, I fix this by replacing the nearly approachable `\$alpha |
\beta | ...' notation with numeric superscripts.
doc/refintro.tex