support simple apposition

gf_attempt/FGrammar.gf

+-- abstract grammar for formulae
+abstract FGrammar = MCats ** {
+    fun
+        fidentifier_to_fcomplexidentifier : FIdentifier -> FComplexIdentifier;    -- n -> mi ( n )
+
+        fcomplexidentifier_to_mathcn : FComplexIdentifier -> MathCN;    -- mi ( n ) => $ mi ( cn )
+}

gf_attempt/FGrammarEng.gf

+concrete FGrammarEng of FGrammar = MCatsEng ** open ParadigmsEng in {
+    oper
+        wrap_mml : Str -> Str -> Str = \wrapper,content -> wrapper ++ "(" ++ content ++ ")";
+    lin
+        fidentifier_to_fcomplexidentifier i = wrap_mml "mi" i;
+        fcomplexidentifier_to_mathcn fci  = lin CN {
+            s = table { singular => table { _ => "$" ++ fci ++ "$" } };
+            g = nonhuman };
+}

gf_attempt/FLexicon.gf

+-- lexicon for formulae (identifiers, operatores, ...)
+
+abstract FLexicon = MCats ** {
+    fun
+        n_FIdentifier : FIdentifier;
+}

gf_attempt/FLexiconEng.gf

+concrete FLexiconEng of FLexicon = MCatsEng ** {
+    lin
+        n_FIdentifier = "n";
+}

gf_attempt/MCats.gf

 -- categories
 abstract MCats = {
     cat
-        DefMObj;      -- definite math object ("the largest element", ...)
-        MObj;         -- math object ("prime number", "group", ...)
-        MObjProp;     -- math object properties ("eve", "prime", "divisble by 2", ...)
-        Statement;    -- statement ("every prime number is an integer")
-        StatementFin; -- finished statement
-        Definition;   -- definition
-        Utterance;    -- (finished) statement or definition
+        DefMObj;            -- definite math object ("the largest element", ...)
+        MObj;               -- math object ("prime number", "group", ...)
+        MObjProp;           -- math object properties ("eve", "prime", "divisble by 2", ...)
+        Statement;          -- statement ("every prime number is an integer")
+        StatementFin;       -- finished statement
+        Definition;         -- definition
+        Utterance;          -- (finished) statement or definition
+
+        FIdentifier;        -- identifier literals in formulae (e.g. "n")
+        FComplexIdentifier; -- complex identifier in formuale (e.g. "x_1")
+        MathCN;             -- math common noun (e.g. $ mo ( n ) $)
 }

gf_attempt/MCatsEng.gf

@@ -7,4 +7,8 @@ concrete MCatsEng of MCats = open SyntaxEng in {
         StatementFin = S;
         Definition = Cl;
         Utterance = Utt;
+
+        FIdentifier = Str;
+        FComplexIdentifier = Str;
+        MathCN = CN;
 }

gf_attempt/MNlp.gf

 -- Collects all the stuff we have for parsing math
-abstract MNlp = NLexicon, NGrammar ** {
+abstract MNlp = NLexicon, NGrammar, FGrammar, FLexicon ** {
     flags
         startcat = Utterance;
 }

gf_attempt/MNlpEng.gf

-concrete MNlpEng of MNlp = NLexiconEng, NGrammarEng ** {
+concrete MNlpEng of MNlp = NLexiconEng, NGrammarEng, FGrammarEng, FLexiconEng ** {
 
 }

gf_attempt/NGrammar.gf

@@ -3,6 +3,7 @@ abstract NGrammar = MCats, Grammar, Extra, ExtraEngAbs ** {
     fun
         restrict_mobj : MObjProp -> MObj -> MObj;             -- "even" -> "integer" -> "even integer"
         def_descr_mobj : MObj -> DefMObj;                     -- "cube" -> "the cube"
+        appo_mobj : MObj -> MathCN -> MObj;                   -- "an integer $ mi ( n ) $
 
         exists_statement : MObj -> Statement;                 -- "integer" -> "there is an integer"
         not_exists_statement : MObj -> Statement;             -- "integer" -> "there is no integer"

gf_attempt/NGrammarEng.gf

@@ -2,6 +2,7 @@ concrete NGrammarEng of NGrammar = MCatsEng, GrammarEng, ExtraEng ** open Syntax
     lin
         restrict_mobj prop obj = mkCN prop obj;
         def_descr_mobj obj = mkNP the_Art obj;
+        appo_mobj obj mcn = lin CN { s = \\number,case_ => obj.s ! number ! case_ ++ mcn.s ! number ! case_; g = obj.g };
 
         exists_statement obj = mkCl obj | ExistsNP (mkNP aSg_Det obj);
         not_exists_statement obj = mkCl (mkNP no_Quant obj) | ExistsNP (mkNP no_Quant obj);