/*  Copyright (C) Wolfgang Menzel, Universität Hamburg, 2003-06-27

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.
*/

%%% a grammar for simple German sentences using
%%% weak unification

:- [unification].

:- nl.
:- write_ln('parsing with weak unification').
:- write_ln('call: ?- s([der, männer, schläft],S,E).')
:- nl.

s(Sentence,Structure,Errors) :- s(Structure,Errors,Sentence,[ ]).
s(s(NP,VP),ErrorsS) -->
  np(NP,_,SUBJagrNP,ErrorsNP),
  vp(VP,SUBJagrVP,ErrorsVP),
    {unify(SUBJagrVP,SUBJagrNP,_,ErrorsNew),
     append(ErrorsNP,ErrorsVP,E),
     append(ErrorsNew,E,ErrorsS)}.

np(np(Det,Noun),NPagr,SUBJagr,ErrorsNP) -->
  det(Det,NPagrD),
  noun(Noun,NPagrN),
    {NPagr=npagr(_,Num,_),
     SUBJagr=subjagr(third,Num),
     unify(NPagrN,NPagrD,NPagr,ErrorsNP)}.

vp(vp(V),SUBJagr,[]) -->
  v(V,SUBJagr).

noun(mann,npagr(nom,sg,masc)) --> [mann].
noun(mann,npagr(acc,sg,masc)) --> [mann].
noun(mann,npagr(dat,sg,masc)) --> [mann].
noun(männer,npagr(nom,pl,masc)) --> [männer].
noun(männer,npagr(gen,pl,masc)) --> [männer].
noun(männer,npagr(acc,pl,masc)) --> [männer].

det(der,npagr(nom,sg,masc)) --> [der].
det(der,npagr(gen,sg,fem)) --> [der].
det(der,npagr(gen,pl,_)) --> [der].
det(die,npagr(nom,pl,_)) --> [die].
det(die,npagr(acc,pl,_)) --> [die].
det(die,npagr(nom,sg,fem)) --> [die].
det(die,npagr(acc,sg,fem)) --> [die].

v(schläft,subjagr(third,sg)) --> [schläft].
v(schlafen,subjagr(third,pl)) --> [schlafen].