installed HilbertPoincareSeries & HilbertPolynomial for submodules

closes #229

Author: mohamed-barakat

Modules/PackageInfo.g

@@ -5,7 +5,7 @@ PackageName := "Modules",
 Subtitle := "A homalg based package for the Abelian category of finitely presented modules over computable rings",
 
 Version := Maximum( [
-  "2019.06.02", ## Mohamed's version
+  "2019.06.04", ## Mohamed's version
 ## this line prevents merge conflicts
   "2014.07.02", ## Markus' version
 ## this line prevents merge conflicts
@@ -16,8 +16,6 @@ Version := Maximum( [
   "2013.05.05", ## Sepp's version
 ## this line prevents merge conflicts
   "2017.06.19", ## Vinay's version
-## this line prevents merge conflicts
-"2015.11.06", ## Homepage update version, to be removed
 ] ),
 
 Date := ~.Version{[ 1 .. 10 ]},

Modules/gap/LIMOD.gi

@@ -1880,6 +1880,17 @@ InstallMethod( HilbertPoincareSeries,
 
 end );
 
+##
+InstallMethod( HilbertPoincareSeries,
+        "for a homalg submodule",
+        [ IsHomalgModule and IsStaticFinitelyPresentedSubobjectRep ],
+        
+  function( M )
+    
+    return HilbertPoincareSeries( SuperObject( M ) ) - HilbertPoincareSeries( FactorObject( M ) );
+    
+end );
+
 ##
 InstallMethod( HilbertPolynomial,
         "for a homalg module",
@@ -1891,6 +1902,17 @@ InstallMethod( HilbertPolynomial,
 
 end );
 
+##
+InstallMethod( HilbertPolynomial,
+        "for a homalg submodule",
+        [ IsHomalgModule and IsStaticFinitelyPresentedSubobjectRep ],
+        
+  function( M )
+    
+    return HilbertPolynomial( SuperObject( M ) ) - HilbertPolynomial( FactorObject( M ) );
+    
+end );
+
 ##
 InstallMethod( DataOfHilbertFunction,
         "for a homalg module",