(Ara) Replace two 2-valued params in VP with one 3-valued param.

* is copula / is have_V2 / is neither

There is no difference; all three options are is mutually exclusive. 
There 2 params in the first place only by accident. First one was added 
by AED 10 years agon, second by me only some weeks ago, without thinking 
that the params are mutually exclusive.

Also tested with gftest, no difference found after 2 hours of running.

src/arabic/IdiomAra.gf

@@ -25,7 +25,7 @@ concrete IdiomAra of Idiom = CatAra ** open
   CleftAdv adv s =
     let comp : Comp = CompAdv (lin Adv {s = adv.s ++ s.s ! Verbal}) ; -- no idea about word order /IL
         pass_V = mkV "مضي" va vi ; -- switch to copula or some other verb if better /IL
-     in predVP emptyNP (UseV pass_V ** {isPred=True ; pred=comp}) ; -- very hacky /IL
+     in predVP emptyNP (UseV pass_V ** {vtype=Copula ; pred=comp}) ; -- very hacky /IL
 
    -- : NP -> Cl ;        -- there is a house
   ExistNP np =

src/arabic/QuestionAra.gf

@@ -14,7 +14,7 @@ lin
 
   -- : IP -> VP -> QCl ;      -- who walks
   QuestVP qp vp =
-   let np = ip2np qp vp.isPred ;
+   let np = ip2np qp (case vp.vtype of {Copula=>True ; _=>False}) ;
        cl = PredVP np vp ;
     in { s = \\t,p,qf => cl.s ! t ! p ! toOrder qf } ;
 

src/arabic/ResAra.gf

@@ -469,19 +469,25 @@ param
          | VPImp
          | VPGer ;
 
+  VType = -- indicates if there is a predicate (xabar): 
+          Copula  -- 1) disappears in equational sentences
+                  -- 2) its argument ('xabar') is in the pred field
+                  -- 3) it is negated with laysa
+         | Have   -- stays in eq. sentence, argument is in obj field, but is negated with laysa.
+         | NotPred ; -- any other verb but copula and have_V2
+
 oper
 
   BaseVP : Type = { -- to minimise duplication of code for VPS
     sc : Preposition ; -- subject case: e.g.  يُمْكِنُ *لِ*Xِ
     obj : Obj;
     pred : Comp;
-    isPred : Bool; -- indicates if there is a predicate (xabar)
+    vtype : VType ; -- copula, have_V2 or normal verb
     s2 : Str
     } ;
 
   VP : Type = BaseVP ** {
     s : PerGenNum => VPForm => Str ;
-    isPoss : Bool; -- special case for have_V2, to get negation right /IL
     } ;
 
   uttVP : VPForm -> VP -> (Gender=>Str) = \vpf,vp ->
@@ -502,7 +508,7 @@ oper
       obj = emptyObj ;
       s2 = [];
       pred = {s = \\_,_ => []} ;
-      isPred,isPoss = False
+      vtype = NotPred
     };
 
   passPredV : Verb -> VP = \v ->
@@ -543,18 +549,18 @@ oper
 
   bindIf : Bool -> Str = \b -> if_then_Str b BIND [] ;
 
-  bindIfPron : NP -> {c2:Preposition; isPred:Bool} -> Str = \np,vp ->
+  bindIfPron : NP -> {c2:Preposition; vtype:VType} -> Str = \np,vp ->
     let notNom : Case -> Bool = \c -> case c of {Nom => False; _=>True} ;
-        bind = case vp.isPred of {
-                 False => bindIf (
-                            orB (andB np.a.isPron (notNom vp.c2.c)) --if np is pron, not in nominative
-                                 vp.c2.binds) ;
-                 True  => [] }
+        bind = case vp.vtype of {
+                 Copula => [] ;
+                 _ => bindIf (orB (andB np.a.isPron (notNom vp.c2.c)) --if np is pron, not in nominative
+                                  vp.c2.binds)
+                 }
      in vp.c2.s ++ bind ++ np.s ! vp.c2.c ;
 
   insertPred : Comp -> VP -> VP = \p,vp -> vp **
     { pred = p;
-      isPred = True
+      vtype = Copula
     };
 
   insertStr : Str -> VP -> VP = \str,vp -> vp **
@@ -584,9 +590,9 @@ oper
                        _    => vp.sc }
               } ;
           subj = np.empty ++ sc.s ++ bindIf sc.binds
-              ++ case vp.isPred of {
-                    False => (proDrop np).s ! sc.c ; -- prodrop if it's not predicative
-                    True  =>           np.s ! sc.c
+              ++ case vp.vtype of {
+                    Copula =>      np.s ! sc.c ;
+                    _ => (proDrop np).s ! sc.c -- prodrop if it's not predicative
                  } ;
       in wordOrder o
            vp.obj.a.isPron np.a.isPron np.isHeavy
@@ -631,8 +637,8 @@ oper
 
   pred : VP -> PerGenNum -> ParamX.Tense -> Polarity -> Str = \vp,pgn,tn,pl ->
     let gn = pgn2gn pgn
-     in case <vp.isPred,tn,pl> of {
-          <True, Pres, Pos> => vp.pred.s ! gn ! Nom; --xabar marfooc
+     in case <vp.vtype,tn,pl> of {
+          <Copula, Pres, Pos> => vp.pred.s ! gn ! Nom; --xabar marfooc
           _                   => vp.pred.s ! gn ! Acc --xabar kaana wa laysa manSoob
         } ;
 
@@ -646,12 +652,12 @@ oper
         lam   = "لَمْ" ;   -- neg. past
         alla  = "أَلَّا" ; -- neg. subjunctive
         lan   = "لَنْ" ;   -- neg. future
-     in case <vp.isPred,tn,pl,o,vp.isPoss> of {
-          <False, Pres, Neg, _, True> => laysa ! Per3 Masc Sg ++ yaktubu ; -- special case for have_V2
-          <False, Pres, Pos, _> => yaktubu ;
-          <False, Pres, Neg, _> => la ++ yaktubu ;
-          <True, Pres, Pos, _> => [] ;    --no verb "to be" in present
-          <True, Pres, Neg, _> => laysa ! pgn ; -- negative copula
+     in case <vp.vtype,tn,pl,o> of {
+          <Have, Pres, Neg, _,> => laysa ! Per3 Masc Sg ++ yaktubu ; -- special case for have_V2
+          <Copula, Pres, Pos, _> => [] ;    --no verb "to be" in present
+          <Copula, Pres, Neg, _> => laysa ! pgn ; -- negative copula
+          <_, Pres, Pos, _> => yaktubu ;
+          <_, Pres, Neg, _> => la ++ yaktubu ;
           <_, Past, Pos, _> => kataba ;
           <_, Past, Neg, _> => lam ++ yaktub ;
           <_, Cond, Pos, _> => yaktuba ;
@@ -682,9 +688,9 @@ oper
   slashV2 : Verb2 -> VPSlash = \v ->
     predV v ** {
       c2 = v.c2 ; agrObj = \\_ => [] ;
-      isPoss = case v.c2.c of {
-                 Nom => True ; -- for have_V2
-                 _   => False } ;
+      vtype = case v.c2.c of {
+                 Nom => Have ; -- for have_V2
+                 _   => NotPred } ;
       } ;
 
   -- Add subject string, fix agreement to the subject,

src/arabic/VerbAra.gf

@@ -16,7 +16,7 @@ concrete VerbAra of Verb = CatAra ** open Prelude, ResAra, ParamX in {
                        ++ vp.s ! pgn ! VPImpf Cnj -- this will agree with the object added by ComplSlash
                        ++ vp.obj.s ;
         obj = emptyObj ;
-        isPred = False ;
+        vtype = NotPred ;
         c2 = v2v.c2 ; -- preposition for the direct object
         sc = v2v.sc
       } ;
@@ -30,7 +30,7 @@ concrete VerbAra of Verb = CatAra ** open Prelude, ResAra, ParamX in {
                       ++ vps.s ! np.a.pgn ! VPImpf Cnj -- verb from old VP agrees with object
                       ++ vps.obj.s ; -- otherwise obj appears in a weird place /IL
         obj = emptyObj ;
-        isPred = False ;
+        vtype = NotPred ;
                     -- preposition for the direct object comes from VP
         sc = v2v.sc
       } ;
@@ -68,7 +68,7 @@ concrete VerbAra of Verb = CatAra ** open Prelude, ResAra, ParamX in {
         s = \\pgn,vpf => vvVP.s ! pgn ! vpf
                       ++ vv.s2  -- أَنْ
                       ++ vp.s ! pgn ! VPImpf Cnj ;
-        isPred = False ;
+        vtype = NotPred ;
         sc = vv.sc
       } ;
 
@@ -92,7 +92,7 @@ concrete VerbAra of Verb = CatAra ** open Prelude, ResAra, ParamX in {
     UseComp xabar =
       case xabar.isNP of {
         False => kaan xabar ;
-        True  => predV copula ** {obj = xabar.obj ; isPred=True}
+        True  => predV copula ** {obj = xabar.obj ; vtype=Copula}
       } ;
 
     UseCopula = predV copula ;