Fix row & rows issues when no rows

solution.pl

@@ -62,13 +62,22 @@ cols(Table, Cols) :-
 Unifies Row, one result at a time, with each row in the given Table.
 If the given table does not exist, the predicate should fail.
 */
+row(Table, _) :-
+	\+ tabl(Table, _),
+	throw("Table doesn't exist"),
+	!. 
+
+row(Table, _) :-
+	tabl(Table, Cols),
+	length(Cols, L),
+	\+ current_predicate(Table/L),
+	!.
+
 row(Table, Row) :-
-    tabl(Table, Cols) ->
-    (
-		length(Cols, L),
-		length(Row, L),
-    	apply(Table, Row) 
-    ); throw("Table doesn't exist").
+    tabl(Table, Cols), 
+	length(Cols, L),
+	length(Row, L),
+	apply(Table, Row).
 
 :- dynamic rows/1.
 /*
@@ -81,6 +90,12 @@ rows(Table) :-
     throw(table_does_not_exist(Table)),
     !.
 
+rows(Table) :-
+	tabl(Table, Cols),
+	length(Cols, L),
+	\+ current_predicate(Table/L),
+	!.
+
 rows(Table) :-
     row(Table, Row),
     writeln(Row),