Allow atomic propositions negated with a combining overline.

* src/ltlparse/ltlscan.ll: Understand the combining overline, and
combining overbar as synonym for =0.
* src/ltlvisit/tostring.cc: Emit a combining overline for
single-letter atomic propositions.
* src/ltlast/atomic_prop.hh (is_atomic_prop): New function.
* doc/tl/tl.tex: Document these two characters.
This commit is contained in:
Alexandre Duret-Lutz 2012-04-29 19:25:43 +02:00
parent 1319e18e1d
commit 6ea88efddc
4 changed files with 39 additions and 6 deletions

View file

@ -381,6 +381,12 @@ syntax \samp{$a$=0}, which is equivalent to \samp{$\NOT a$}. Also
\samp{$a$=1} is equivalent to just \samp{a}. These two syntaxes help
us read formul\ae{} written using Wring's syntax.
When using UTF-8 input, a \samp{=0} that follow a single-letter atomic
proposition may be replaced by a combining overline \uni{0305} or a
combining overbar \uni{0304}. When instructed to emit UTF-8, Spot
will output \samp{$\bar{\mathtt{a}}$} using a combining overline
instead of \samp{$\lnot$a} for any single-letter atomic proposition.
\label{def:boolform}
When a formula is built using only Boolean constants
(section~\ref{sec:bool}), atomic proposition (section~\ref{sec:ap}),