diff --git a/NEWS b/NEWS index a1dc07b00..6e577b1d5 100644 --- a/NEWS +++ b/NEWS @@ -1,14 +1,49 @@ New in spot 0.8.3a: * New features: + - Operators from the linear fragment of PSL are supported. This + basically extends LTL with Sequential Extended Regulat + Expressions (SERE), and a couple of operators to bridge SERE and + LTL. See doc/tl/tl.pdf for the list of operators and their + semantics. + - The constructors for temporal formulae will perform some trivial + simplifications based on associativity, commutativity, + idempotence, and neutral elements. See doc/tl/tl.pdf for the + list of such simplifications. + - Formula rewritings have been completely revamped, and augmented + with rules for PSL operators (and some new LTL rules as well). + See doc/tl/tl.pdf for the list of the rewritings implemented. + - Some of these rewritings that may produce larger formulas + (For instance to rewrite "{a;b;c}" as "a & X(b & Xc)".) + may be explicitely disabled with a new option. + - The src/ltltest/randltl tool can now generate random SEREs + and random PSL formulae. + - Only one translator (ltl2tgba_fm) has been augmented to + translate the new SERE and PSL operators. The internal + translation from SERE to DFA is likely to be rewriten in a + future version. + - A new function, length_boolone(), computes the size of an + LTL/PSL formula while considering that any Boolean term + has length 1. - A new direct simulation reduction has been implemented. It - works directly on TGBA. It's in src/tgbaalgos/simlation.hh, + works directly on TGBAs. It is in src/tgbaalgos/simlation.hh, and it can be tested via ltl2tgba's -RDS option. + - changes to the on-line translator: + + SVG output is available + + can display some properties of a formula + + new options for direct simulation and larger rewritings - configure --without-included-lbtt will prevent LBTT from being configured and built. This helps on systems (such as MinGW) where LBTT cannot be built. The test-suite will skip any LBTT-based test if LBTT is missing. * Interface chances: + - The new entry point for LTL/PSL simplifications is the function + ltl_simplifier::simplify() declared in src/ltlvisit/simplify.hh. + The ltl_simplifier class implements a cache. + Functions such as reduce() or reduce_tau03() are deprecated. + - Formula instances now have many methods to inspect their + properties (membership to syntactic classes, absence of X + operator, etc...) in constant time. - The old game-theory-based implementations for direct and delayed simulation reductions have been removed. The old direct simulation would only work on degeneralized automata, and yet