**November 6, 2006**

Version 1.3 of BB1 released. Couple of bug fixes.
New versions of `semLexHole.pl`, `alphaConversion.pl`,
`betaConversion.pl` and `betaConversionTestSuite.pl`.

**November 5, 2006**

Arguments are swapped in the macro for transitive verbs in `semLexHole.pl` in
version 1.2 of BB1. Corrected macro:

semLex(tv,M):-
M = [symbol:Sym,
sem:lam(Z,lam(X,app(Z,lam(Y,lam(H,lam(L,and(pred2(L,Sym,X,Y),leq(L,H))))))))].

Reported by Mike White.
**November 17, 2005**

Added link to interview with Patrick Blackburn in
PhiNews

**September 9, 2005**

Discovered bug in `alphabeticVariants/2`.
Some formulas with identical free variables were wrongly classified as
non-alphabetic variants. The revised code for this predicate is:

alphabeticVariants(Term1,Term2):-
alphaConvert(Term1,[],[]-Free1,Term3),
alphaConvert(Term2,[],[]-Free2,Term4),
Free1==Free2,
numbervars(Free1,0,N),
numbervars(Term3,N,M),
numbervars(Term4,N,M),
Term3=Term4.

**September 8, 2005**

There appears to be a bug in `betaConvert/3`. For input such
as `app(app(X,Y),Z)` it returns `no` rather than succeeding
and returning the same term. The current solution is this code:

betaConvert(X,Y,[]):-
var(X), !,
Y=X.
betaConvert(Expression,Result,Stack):-
nonvar(Expression),
Expression = app(Functor,Argument),
alphaConvert(Functor,Converted),
betaConvert(Converted,Result,[Argument|Stack]), !.
betaConvert(Expression,Result,[X|Stack]):-
nonvar(Expression),
Expression = lam(X,Formula),
betaConvert(Formula,Result,Stack), !.
betaConvert(Formula,Result,[]):-
nonvar(Formula), !,
compose(Formula,Functor,Formulas),
betaConvertList(Formulas,ResultFormulas),
compose(Result,Functor,ResultFormulas).
betaConvert(Exp,app(Exp,Y),[X]):-
betaConvert(X,Y).

Thanks to Sebastien Hinderer and Carlos Areces for reporting this.
**August 8, 2005**

Version 1.2 of BB1 released. Deals with the
problem of numbervars in `fol2otter.pl`, `fol2bliksem.pl`, `fol2tptp.pl`,
and `comsemPredicates.pl`. Also fixed a bug to do with equality in
`backgroundKnowledge.pl`.

**July 9, 2005**

There is a problem with numbervars when using
newer versions of SWI Prolog. Thanks to John Rood for reporting this.

**June 10, 2005**

Version 1.1 of BB1 released. Major changes in the perl programs.

**March 15, 2005**

Representation and Inference now available at CSLI publications.