From 157a2ed349418611302476dce79fced1d95a4ecc Mon Sep 17 00:00:00 2001
From: ajreynol <andrew.j.reynolds@gmail.com>
Date: Thu, 10 Dec 2015 13:32:42 +0100
Subject: [PATCH] Add option fmf-empty-sorts.

---
 src/theory/quantifiers/model_engine.cpp | 11 ++++++++++-
 src/theory/quantifiers/options          |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/theory/quantifiers/model_engine.cpp b/src/theory/quantifiers/model_engine.cpp
index a3a18cf30..f5a063eb8 100644
--- a/src/theory/quantifiers/model_engine.cpp
+++ b/src/theory/quantifiers/model_engine.cpp
@@ -227,7 +227,16 @@ bool ModelEngine::considerQuantifiedFormula( Node q ) {
   if( !d_quantEngine->getModelBuilder()->isQuantifierActive( q ) ){ //!d_quantEngine->getModel()->isQuantifierActive( q );
     return false;
   }else{
-    if( options::fmfFunWellDefinedRelevant() ){
+    if( options::fmfEmptySorts() ){
+      for( unsigned i=0; i<q[0].getNumChildren(); i++ ){
+        TypeNode tn = q[0][i].getType();
+        //we are allowed to assume the type is empty
+        if( d_quantEngine->getModel()->d_rep_set.getNumRelevantGroundReps( tn )==0 ){
+          Trace("model-engine-debug") << "Empty domain quantified formula : " << q << std::endl;
+          return false;
+        }
+      }
+    }else if( options::fmfFunWellDefinedRelevant() ){
       if( q[0].getNumChildren()==1 ){
         TypeNode tn = q[0][0].getType();
         if( tn.getAttribute(AbsTypeFunDefAttribute()) ){
diff --git a/src/theory/quantifiers/options b/src/theory/quantifiers/options
index be6f71c39..065da0d5a 100644
--- a/src/theory/quantifiers/options
+++ b/src/theory/quantifiers/options
@@ -127,6 +127,8 @@ option fmfFunWellDefined --fmf-fun bool :default false :read-write
  find models for recursively defined functions, assumes functions are admissible
 option fmfFunWellDefinedRelevant --fmf-fun-rlv bool :default false
  find models for recursively defined functions, assumes functions are admissible, allows empty type when function is irrelevant
+option fmfEmptySorts --fmf-empty-sorts bool :default false
+ allow finite model finding to assume sorts that do not occur in ground assertions are empty
  
 option mbqiMode --mbqi=MODE CVC4::theory::quantifiers::MbqiMode :read-write :default CVC4::theory::quantifiers::MBQI_FMC :include "theory/quantifiers/modes.h" :handler CVC4::theory::quantifiers::stringToMbqiMode :handler-include "theory/quantifiers/options_handlers.h" :predicate CVC4::theory::quantifiers::checkMbqiMode :predicate-include "theory/quantifiers/options_handlers.h"
  choose mode for model-based quantifier instantiation
-- 
2.30.2