From: Brian Demsky <bdemsky@uci.edu>
Date: Mon, 8 Jan 2018 23:44:47 +0000 (-0800)
Subject: edits
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f9598387d8224d24fe96cd7a849bded46c6ade2b;p=satune.git

edits
---

diff --git a/src/Backend/constraint.cc b/src/Backend/constraint.cc
index 386706d..390b831 100644
--- a/src/Backend/constraint.cc
+++ b/src/Backend/constraint.cc
@@ -2,7 +2,6 @@
 #include <string.h>
 #include <stdlib.h>
 #include "inc_solver.h"
-#include "cnfexpr.h"
 #include "common.h"
 #include "qsort.h"
 /*
@@ -44,21 +43,13 @@
 VectorImpl(Edge, Edge, 16)
 Edge E_True = {(Node *)(uintptr_t) EDGE_IS_VAR_CONSTANT};
 Edge E_False = {(Node *)(uintptr_t) (EDGE_IS_VAR_CONSTANT | NEGATE_EDGE)};
-Edge E_BOGUS = {(Node *)0x12345673};
+Edge E_BOGUS = {(Node *)0xffff5673};
 Edge E_NULL = {(Node *)NULL};
 
 
 CNF *createCNF() {
 	CNF *cnf = (CNF *) ourmalloc(sizeof(CNF));
 	cnf->varcount = 1;
-	cnf->capacity = DEFAULT_CNF_ARRAY_SIZE;
-	cnf->mask = cnf->capacity - 1;
-	cnf->node_array = (Node **) ourcalloc(1, sizeof(Node *) * cnf->capacity);
-	cnf->size = 0;
-	cnf->maxsize = (uint)(((double)cnf->capacity) * LOAD_FACTOR);
-	cnf->enableMatching = true;
-	initDefVectorEdge(&cnf->constraints);
-	initDefVectorEdge(&cnf->args);
 	cnf->solver = allocIncrementalSolver();
 	cnf->solveTime = 0;
 	cnf->encodeTime = 0;
@@ -66,130 +57,29 @@ CNF *createCNF() {
 }
 
 void deleteCNF(CNF *cnf) {
-	for (uint i = 0; i < cnf->capacity; i++) {
-		Node *n = cnf->node_array[i];
-		if (n != NULL)
-			ourfree(n);
-	}
-	deleteVectorArrayEdge(&cnf->constraints);
-	deleteVectorArrayEdge(&cnf->args);
 	deleteIncrementalSolver(cnf->solver);
-	ourfree(cnf->node_array);
 	ourfree(cnf);
 }
 
 void resetCNF(CNF *cnf) {
-	for (uint i = 0; i < cnf->capacity; i++) {
-		Node *n = cnf->node_array[i];
-		if (n != NULL)
-			ourfree(n);
-	}
-	clearVectorEdge(&cnf->constraints);
-	clearVectorEdge(&cnf->args);
 	resetSolver(cnf->solver);
-	memset(cnf->node_array, 0, sizeof(Node *) * cnf->capacity);
-
 	cnf->varcount = 1;
-	cnf->size = 0;
-	cnf->enableMatching = true;
 	cnf->solveTime = 0;
 	cnf->encodeTime = 0;
 }
 
-void resizeCNF(CNF *cnf, uint newCapacity) {
-	Node **old_array = cnf->node_array;
-	Node **new_array = (Node **) ourcalloc(1, sizeof(Node *) * newCapacity);
-	uint oldCapacity = cnf->capacity;
-	uint newMask = newCapacity - 1;
-	for (uint i = 0; i < oldCapacity; i++) {
-		Node *n = old_array[i];
-		if (n == NULL)
-			continue;
-		uint hashCode = n->hashCode;
-		uint newindex = hashCode & newMask;
-		for (;; newindex = (newindex + 1) & newMask) {
-			if (new_array[newindex] == NULL) {
-				new_array[newindex] = n;
-				break;
-			}
-		}
-	}
-	ourfree(old_array);
-	cnf->node_array = new_array;
-	cnf->capacity = newCapacity;
-	cnf->maxsize = (uint)(((double)cnf->capacity) * LOAD_FACTOR);
-	cnf->mask = newMask;
-}
-
-Node *allocNode(NodeType type, uint numEdges, Edge *edges, uint hashcode) {
+Node *allocNode(NodeType type, uint numEdges, Edge *edges) {
 	Node *n = (Node *)ourmalloc(sizeof(Node) + sizeof(Edge) * numEdges);
 	memcpy(n->edges, edges, sizeof(Edge) * numEdges);
-	n->flags.type = type;
-	n->flags.wasExpanded = 0;
-	n->flags.cnfVisitedDown = 0;
-	n->flags.cnfVisitedUp = 0;
-	n->flags.varForced = 0;
 	n->numEdges = numEdges;
-	n->hashCode = hashcode;
-	n->intAnnot[0] = 0;n->intAnnot[1] = 0;
-	n->ptrAnnot[0] = NULL;n->ptrAnnot[1] = NULL;
 	return n;
 }
 
 Edge createNode(CNF *cnf, NodeType type, uint numEdges, Edge *edges) {
-	if (cnf->size > cnf->maxsize) {
-		resizeCNF(cnf, cnf->capacity << 1);
-	}
-	uint hashvalue = hashNode(type, numEdges, edges);
-	uint mask = cnf->mask;
-	uint index = hashvalue & mask;
-	Node **n_ptr;
-	for (;; index = (index + 1) & mask) {
-		n_ptr = &cnf->node_array[index];
-		if (*n_ptr != NULL) {
-			if ((*n_ptr)->hashCode == hashvalue) {
-				if (compareNodes(*n_ptr, type, numEdges, edges)) {
-					Edge e = {*n_ptr};
-					return e;
-				}
-			}
-		} else {
-			break;
-		}
-	}
-	*n_ptr = allocNode(type, numEdges, edges, hashvalue);
-	cnf->size++;
-	Edge e = {*n_ptr};
+	Edge e = {allocNode(type, numEdges, edges)};
 	return e;
 }
 
-uint hashNode(NodeType type, uint numEdges, Edge *edges) {
-	uint hash = type;
-	hash += hash << 10;
-	hash ^= hash >> 6;
-	for (uint i = 0; i < numEdges; i++) {
-		uint c = (uint) ((uintptr_t) edges[i].node_ptr);
-		hash += c;
-		hash += hash << 10;
-		hash += hash >> 6;
-	}
-	hash += hash << 3;
-	hash ^= hash >> 11;
-	hash += hash << 15;
-	return hash;
-}
-
-bool compareNodes(Node *node, NodeType type, uint numEdges, Edge *edges) {
-	if (node->flags.type != type || node->numEdges != numEdges)
-		return false;
-	Edge *nodeedges = node->edges;
-	for (uint i = 0; i < numEdges; i++) {
-		if (!equalsEdge(nodeedges[i], edges[i]))
-			return false;
-	}
-	return true;
-}
-
 Edge constraintOR(CNF *cnf, uint numEdges, Edge *edges) {
 	Edge edgearray[numEdges];
 
@@ -251,7 +141,7 @@ Edge constraintAND(CNF *cnf, uint numEdges, Edge *edges) {
 	if (lowindex == 1)
 		return edges[0];
 
-	if (cnf->enableMatching && lowindex == 2 &&
+	if (lowindex == 2 &&
 			isNegNodeEdge(edges[0]) && isNegNodeEdge(edges[1]) &&
 			getNodeType(edges[0]) == NodeType_AND &&
 			getNodeType(edges[1]) == NodeType_AND &&
@@ -351,7 +241,7 @@ Edge constraintITE(CNF *cnf, Edge cond, Edge thenedge, Edge elseedge) {
 }
 
 void addConstraintCNF(CNF *cnf, Edge constraint) {
-	pushVectorEdge(&cnf->constraints, constraint);
+	//	pushVectorEdge(&cnf->constraints, constraint);
 #ifdef CONFIG_DEBUG
 	model_print("****SATC_ADDING NEW Constraint*****\n");
 	printCNF(constraint);
@@ -367,8 +257,6 @@ Edge constraintNewVar(CNF *cnf) {
 
 int solveCNF(CNF *cnf) {
 	long long startTime = getTimeNano();
-	countPass(cnf);
-	convertPass(cnf, false);
 	finishedClauses(cnf->solver);
 	long long startSolve = getTimeNano();
 	int result = solve(cnf->solver);
@@ -387,367 +275,6 @@ bool getValueCNF(CNF *cnf, Edge var) {
 	return isneg ^ getValueSolver(cnf->solver, l);
 }
 
-void countPass(CNF *cnf) {
-	uint numConstraints = getSizeVectorEdge(&cnf->constraints);
-	VectorEdge *ve = allocDefVectorEdge();
-	for (uint i = 0; i < numConstraints; i++) {
-		countConstraint(cnf, ve, getVectorEdge(&cnf->constraints, i));
-	}
-	deleteVectorEdge(ve);
-}
-
-void countConstraint(CNF *cnf, VectorEdge *stack, Edge eroot) {
-	//Skip constants and variables...
-	if (edgeIsVarConst(eroot))
-		return;
-
-	clearVectorEdge(stack);pushVectorEdge(stack, eroot);
-
-	bool isMatching = cnf->enableMatching;
-
-	while (getSizeVectorEdge(stack) != 0) {
-		Edge e = lastVectorEdge(stack); popVectorEdge(stack);
-		bool polarity = isNegEdge(e);
-		Node *n = getNodePtrFromEdge(e);
-		if (getExpanded(n,  polarity)) {
-			if (n->flags.type == NodeType_IFF ||
-					n->flags.type == NodeType_ITE) {
-				Edge pExp = {(Node *)n->ptrAnnot[polarity]};
-				getNodePtrFromEdge(pExp)->intAnnot[0]++;
-			} else {
-				n->intAnnot[polarity]++;
-			}
-		} else {
-			setExpanded(n, polarity);
-
-			if (n->flags.type == NodeType_ITE ||
-					n->flags.type == NodeType_IFF) {
-				n->intAnnot[polarity] = 0;
-				Edge cond = n->edges[0];
-				Edge thenedge = n->edges[1];
-				Edge elseedge = n->flags.type == NodeType_IFF ? constraintNegate(thenedge) : n->edges[2];
-				thenedge = constraintNegateIf(thenedge, !polarity);
-				elseedge = constraintNegateIf(elseedge, !polarity);
-				thenedge = constraintAND2(cnf, cond, thenedge);
-				cond = constraintNegate(cond);
-				elseedge = constraintAND2(cnf, cond, elseedge);
-				thenedge = constraintNegate(thenedge);
-				elseedge = constraintNegate(elseedge);
-				cnf->enableMatching = false;
-				Edge succ1 = constraintAND2(cnf, thenedge, elseedge);
-				n->ptrAnnot[polarity] = succ1.node_ptr;
-				cnf->enableMatching = isMatching;
-				pushVectorEdge(stack, succ1);
-				if (getExpanded(n, !polarity)) {
-					Edge succ2 = {(Node *)n->ptrAnnot[!polarity]};
-					Node *n1 = getNodePtrFromEdge(succ1);
-					Node *n2 = getNodePtrFromEdge(succ2);
-					n1->ptrAnnot[0] = succ2.node_ptr;
-					n2->ptrAnnot[0] = succ1.node_ptr;
-					n1->ptrAnnot[1] = succ2.node_ptr;
-					n2->ptrAnnot[1] = succ1.node_ptr;
-				}
-			} else {
-				n->intAnnot[polarity] = 1;
-				for (uint i = 0; i < n->numEdges; i++) {
-					Edge succ = n->edges[i];
-					if (!edgeIsVarConst(succ)) {
-						succ = constraintNegateIf(succ, polarity);
-						pushVectorEdge(stack, succ);
-					}
-				}
-			}
-		}
-	}
-}
-
-void convertPass(CNF *cnf, bool backtrackLit) {
-	uint numConstraints = getSizeVectorEdge(&cnf->constraints);
-	VectorEdge *ve = allocDefVectorEdge();
-	for (uint i = 0; i < numConstraints; i++) {
-		convertConstraint(cnf, ve, getVectorEdge(&cnf->constraints, i), backtrackLit);
-	}
-	deleteVectorEdge(ve);
-}
-
-void convertConstraint(CNF *cnf, VectorEdge *stack, Edge root, bool backtrackLit) {
-	Node *nroot = getNodePtrFromEdge(root);
-
-	if (isNodeEdge(root) && (nroot->flags.type == NodeType_ITE || nroot->flags.type == NodeType_IFF)) {
-		nroot = (Node *) nroot->ptrAnnot[isNegEdge(root)];
-		root = (Edge) { nroot };
-	}
-	if (edgeIsConst(root)) {
-		if (isNegEdge(root)) {
-			//trivally unsat
-			Edge newvar = constraintNewVar(cnf);
-			Literal var = getEdgeVar(newvar);
-			Literal clause[] = {var};
-			addArrayClauseLiteral(cnf->solver, 1, clause);
-			clause[0] = -var;
-			addArrayClauseLiteral(cnf->solver, 1, clause);
-			return;
-		} else {
-			//trivially true
-			return;
-		}
-	} else if (edgeIsVarConst(root)) {
-		Literal clause[] = { getEdgeVar(root)};
-		addArrayClauseLiteral(cnf->solver, 1, clause);
-		return;
-	}
-
-	clearVectorEdge(stack);pushVectorEdge(stack, root);
-	while (getSizeVectorEdge(stack) != 0) {
-		Edge e = lastVectorEdge(stack);
-		Node *n = getNodePtrFromEdge(e);
-
-		if (edgeIsVarConst(e)) {
-			popVectorEdge(stack);
-			continue;
-		} else if (n->flags.type == NodeType_ITE ||
-							 n->flags.type == NodeType_IFF) {
-			popVectorEdge(stack);
-			if (n->ptrAnnot[0] != NULL)
-				pushVectorEdge(stack, (Edge) {(Node *)n->ptrAnnot[0]});
-			if (n->ptrAnnot[1] != NULL)
-				pushVectorEdge(stack, (Edge) {(Node *)n->ptrAnnot[1]});
-			continue;
-		}
-
-		bool needPos = (n->intAnnot[0] > 0);
-		bool needNeg = (n->intAnnot[1] > 0);
-		if ((!needPos || n->flags.cnfVisitedUp & 1) &&
-				(!needNeg || n->flags.cnfVisitedUp & 2)) {
-			popVectorEdge(stack);
-		} else if ((needPos && !(n->flags.cnfVisitedDown & 1)) ||
-							 (needNeg && !(n->flags.cnfVisitedDown & 2))) {
-			if (needPos)
-				n->flags.cnfVisitedDown |= 1;
-			if (needNeg)
-				n->flags.cnfVisitedDown |= 2;
-			for (uint i = 0; i < n->numEdges; i++) {
-				Edge arg = n->edges[i];
-				arg = constraintNegateIf(arg, isNegEdge(e));
-				pushVectorEdge(stack, arg);	//WARNING, THIS LOOKS LIKE A BUG IN THE ORIGINAL CODE
-			}
-		} else {
-			popVectorEdge(stack);
-			produceCNF(cnf, e);
-		}
-	}
-	CNFExpr *cnfExp = (CNFExpr *) nroot->ptrAnnot[isNegEdge(root)];
-	ASSERT(cnfExp != NULL);
-	if (isProxy(cnfExp)) {
-		Literal l = getProxy(cnfExp);
-		Literal clause[] = {l};
-		addArrayClauseLiteral(cnf->solver, 1, clause);
-	} else if (backtrackLit) {
-		Literal l = introProxy(cnf, root, cnfExp, isNegEdge(root));
-		Literal clause[] = {l};
-		addArrayClauseLiteral(cnf->solver, 1, clause);
-	} else {
-		outputCNF(cnf, cnfExp);
-	}
-
-	if (!((intptr_t) cnfExp & 1)) {
-		deleteCNFExpr(cnfExp);
-		nroot->ptrAnnot[isNegEdge(root)] = NULL;
-	}
-}
-
-
-Literal introProxy(CNF *cnf, Edge e, CNFExpr *exp, bool isNeg) {
-	Literal l = 0;
-	Node *n = getNodePtrFromEdge(e);
-
-	if (n->flags.cnfVisitedUp & (1 << !isNeg)) {
-		CNFExpr *otherExp = (CNFExpr *) n->ptrAnnot[!isNeg];
-		if (isProxy(otherExp))
-			l = -getProxy(otherExp);
-	} else {
-		Edge semNeg = {(Node *) n->ptrAnnot[isNeg]};
-		Node *nsemNeg = getNodePtrFromEdge(semNeg);
-		if (nsemNeg != NULL) {
-			if (nsemNeg->flags.cnfVisitedUp & (1 << isNeg)) {
-				CNFExpr *otherExp = (CNFExpr *) nsemNeg->ptrAnnot[isNeg];
-				if (isProxy(otherExp))
-					l = -getProxy(otherExp);
-			} else if (nsemNeg->flags.cnfVisitedUp & (1 << !isNeg)) {
-				CNFExpr *otherExp = (CNFExpr *) nsemNeg->ptrAnnot[!isNeg];
-				if (isProxy(otherExp))
-					l = getProxy(otherExp);
-			}
-		}
-	}
-
-	if (l == 0) {
-		Edge newvar = constraintNewVar(cnf);
-		l = getEdgeVar(newvar);
-	}
-	// Output the constraints on the auxiliary variable
-	constrainCNF(cnf, l, exp);
-	deleteCNFExpr(exp);
-
-	n->ptrAnnot[isNeg] = (void *) ((intptr_t) (l << 1) | 1);
-
-	return l;
-}
-
-void produceCNF(CNF *cnf, Edge e) {
-	CNFExpr *expPos = NULL;
-	CNFExpr *expNeg = NULL;
-	Node *n = getNodePtrFromEdge(e);
-
-	if (n->intAnnot[0] > 0) {
-		expPos = produceConjunction(cnf, e);
-	}
-
-	if (n->intAnnot[1]  > 0) {
-		expNeg = produceDisjunction(cnf, e);
-	}
-
-	/// @todo Propagate constants across semantic negations (this can
-	/// be done similarly to the calls to propagate shown below).  The
-	/// trick here is that we need to figure out how to get the
-	/// semantic negation pointers, and ensure that they can have CNF
-	/// produced for them at the right point
-	///
-	/// propagate(solver, expPos, snPos, false) || propagate(solver, expNeg, snNeg, false)
-
-	// propagate from positive to negative, negative to positive
-	if (!propagate(cnf, &expPos, expNeg, true))
-		propagate(cnf, &expNeg, expPos, true);
-
-	// The polarity heuristic entails visiting the discovery polarity first
-	if (isPosEdge(e)) {
-		saveCNF(cnf, expPos, e, false);
-		saveCNF(cnf, expNeg, e, true);
-	} else {
-		saveCNF(cnf, expNeg, e, true);
-		saveCNF(cnf, expPos, e, false);
-	}
-}
-
-bool propagate(CNF *cnf, CNFExpr **dest, CNFExpr *src, bool negate) {
-	if (src != NULL && !isProxy(src) && getLitSizeCNF(src) == 0) {
-		if (*dest == NULL) {
-			*dest = allocCNFExprBool(negate ? alwaysFalseCNF(src) : alwaysTrueCNF(src));
-		} else if (isProxy(*dest)) {
-			bool alwaysTrue = (negate ? alwaysFalseCNF(src) : alwaysTrueCNF(src));
-			if (alwaysTrue) {
-				Literal clause[] = {getProxy(*dest)};
-				addArrayClauseLiteral(cnf->solver, 1, clause);
-			} else {
-				Literal clause[] = {-getProxy(*dest)};
-				addArrayClauseLiteral(cnf->solver, 1, clause);
-			}
-
-			*dest = allocCNFExprBool(negate ? alwaysFalseCNF(src) : alwaysTrueCNF(src));
-		} else {
-			clearCNFExpr(*dest, negate ? alwaysFalseCNF(src) : alwaysTrueCNF(src));
-		}
-		return true;
-	}
-	return false;
-}
-
-void saveCNF(CNF *cnf, CNFExpr *exp, Edge e, bool sign) {
-	Node *n = getNodePtrFromEdge(e);
-	n->flags.cnfVisitedUp |= (1 << sign);
-	if (exp == NULL || isProxy(exp)) return;
-
-	if (exp->litSize == 1) {
-		Literal l = getLiteralLitVector(&exp->singletons, 0);
-		deleteCNFExpr(exp);
-		n->ptrAnnot[sign] = (void *) ((((intptr_t) l) << 1) | 1);
-	} else if (exp->litSize != 0 && (n->intAnnot[sign] > 1 || n->flags.varForced)) {
-		introProxy(cnf, e, exp, sign);
-	} else {
-		n->ptrAnnot[sign] = exp;
-	}
-}
-
-void constrainCNF(CNF *cnf, Literal lcond, CNFExpr *expr) {
-	if (alwaysTrueCNF(expr)) {
-		return;
-	} else if (alwaysFalseCNF(expr)) {
-		Literal clause[] = {-lcond};
-		addArrayClauseLiteral(cnf->solver, 1, clause);
-		return;
-	}
-
-	for (uint i = 0; i < getSizeLitVector(&expr->singletons); i++) {
-		Literal l = getLiteralLitVector(&expr->singletons,i);
-		Literal clause[] = {-lcond, l};
-		addArrayClauseLiteral(cnf->solver, 2, clause);
-	}
-	for (uint i = 0; i < getSizeVectorLitVector(&expr->clauses); i++) {
-		LitVector *lv = getVectorLitVector(&expr->clauses,i);
-		addClauseLiteral(cnf->solver, -lcond);//Add first literal
-		addArrayClauseLiteral(cnf->solver, getSizeLitVector(lv), lv->literals);	//Add rest
-	}
-}
-
-void outputCNF(CNF *cnf, CNFExpr *expr) {
-	for (uint i = 0; i < getSizeLitVector(&expr->singletons); i++) {
-		Literal l = getLiteralLitVector(&expr->singletons,i);
-		Literal clause[] = {l};
-		addArrayClauseLiteral(cnf->solver, 1, clause);
-	}
-	for (uint i = 0; i < getSizeVectorLitVector(&expr->clauses); i++) {
-		LitVector *lv = getVectorLitVector(&expr->clauses,i);
-		addArrayClauseLiteral(cnf->solver, getSizeLitVector(lv), lv->literals);
-	}
-}
-
-CNFExpr *fillArgs(CNF *cnf, Edge e, bool isNeg, Edge *largestEdge) {
-	clearVectorEdge(&cnf->args);
-
-	*largestEdge = (Edge) {(Node *) NULL};
-	CNFExpr *largest = NULL;
-	Node *n = getNodePtrFromEdge(e);
-	int i = n->numEdges;
-	while (i != 0) {
-		Edge arg = n->edges[--i];
-		arg = constraintNegateIf(arg, isNeg);
-		Node *narg = getNodePtrFromEdge(arg);
-
-		if (edgeIsVarConst(arg)) {
-			pushVectorEdge(&cnf->args, arg);
-			continue;
-		}
-
-		if (narg->flags.type == NodeType_ITE || narg->flags.type == NodeType_IFF) {
-			arg = (Edge) {(Node *) narg->ptrAnnot[isNegEdge(arg)]};
-		}
-
-		if (narg->intAnnot[isNegEdge(arg)] == 1) {
-			CNFExpr *argExp = (CNFExpr *) narg->ptrAnnot[isNegEdge(arg)];
-			if (!isProxy(argExp)) {
-				if (largest == NULL) {
-					largest = argExp;
-					*largestEdge = arg;
-					continue;
-				} else if (argExp->litSize > largest->litSize) {
-					pushVectorEdge(&cnf->args, *largestEdge);
-					largest = argExp;
-					*largestEdge = arg;
-					continue;
-				}
-			}
-		}
-		pushVectorEdge(&cnf->args, arg);
-	}
-
-	if (largest != NULL) {
-		Node *nlargestEdge = getNodePtrFromEdge(*largestEdge);
-		nlargestEdge->ptrAnnot[isNegEdge(*largestEdge)] = NULL;
-	}
-
-	return largest;
-}
-
 void printCNF(Edge e) {
 	if (edgeIsVarConst(e)) {
 		Literal l = getEdgeVar(e);
@@ -800,92 +327,6 @@ void printCNF(Edge e) {
 	model_print(")");
 }
 
-CNFExpr *produceConjunction(CNF *cnf, Edge e) {
-	Edge largestEdge;
-
-	CNFExpr *accum = fillArgs(cnf, e, false, &largestEdge);
-	if (accum == NULL)
-		accum = allocCNFExprBool(true);
-
-	int i = getSizeVectorEdge(&cnf->args);
-	while (i != 0) {
-		Edge arg = getVectorEdge(&cnf->args, --i);
-		if (edgeIsVarConst(arg)) {
-			conjoinCNFLit(accum, getEdgeVar(arg));
-		} else {
-			Node *narg = getNodePtrFromEdge(arg);
-			CNFExpr *argExp = (CNFExpr *) narg->ptrAnnot[isNegEdge(arg)];
-
-			bool destroy = (--narg->intAnnot[isNegEdge(arg)] == 0);
-			if (isProxy(argExp)) {// variable has been introduced
-				conjoinCNFLit(accum, getProxy(argExp));
-			} else {
-				conjoinCNFExpr(accum, argExp, destroy);
-				if (destroy)
-					narg->ptrAnnot[isNegEdge(arg)] = NULL;
-			}
-		}
-	}
-
-	return accum;
-}
-
-#define CLAUSE_MAX 3
-
-CNFExpr *produceDisjunction(CNF *cnf, Edge e) {
-	Edge largestEdge;
-	CNFExpr *accum = fillArgs(cnf, e, true, &largestEdge);
-	if (accum == NULL)
-		accum = allocCNFExprBool(false);
-
-	// This is necessary to check to make sure that we don't start out
-	// with an accumulator that is "too large".
-
-	/// @todo Strictly speaking, introProxy doesn't *need* to free
-	/// memory, then this wouldn't have to reallocate CNFExpr
-
-	/// @todo When this call to introProxy is made, the semantic
-	/// negation pointer will have been destroyed.  Thus, it will not
-	/// be possible to use the correct proxy.  That should be fixed.
-
-	// at this point, we will either have NULL, or a destructible expression
-	if (getClauseSizeCNF(accum) > CLAUSE_MAX)
-		accum = allocCNFExprLiteral(introProxy(cnf, largestEdge, accum, isNegEdge(largestEdge)));
-
-	int i = getSizeVectorEdge(&cnf->args);
-	while (i != 0) {
-		Edge arg = getVectorEdge(&cnf->args, --i);
-		Node *narg = getNodePtrFromEdge(arg);
-		if (edgeIsVarConst(arg)) {
-			disjoinCNFLit(accum, getEdgeVar(arg));
-		} else {
-			CNFExpr *argExp = (CNFExpr *) narg->ptrAnnot[isNegEdge(arg)];
-
-			bool destroy = (--narg->intAnnot[isNegEdge(arg)] == 0);
-			if (isProxy(argExp)) {// variable has been introduced
-				disjoinCNFLit(accum, getProxy(argExp));
-			} else if (argExp->litSize == 0) {
-				disjoinCNFExpr(accum, argExp, destroy);
-			} else {
-				// check to see if we should introduce a proxy
-				int aL = accum->litSize;			// lits in accum
-				int eL = argExp->litSize;			// lits in argument
-				int aC = getClauseSizeCNF(accum);		// clauses in accum
-				int eC = getClauseSizeCNF(argExp);	// clauses in argument
-				//POSSIBLE BUG #2 (eL * aC +aL * eC > eL +aC +aL +aC)
-				if (eC > CLAUSE_MAX || (eL * aC + aL * eC > eL + eC + aL + aC)) {
-					disjoinCNFLit(accum, introProxy(cnf, arg, argExp, isNegEdge(arg)));
-				} else {
-					disjoinCNFExpr(accum, argExp, destroy);
-					if (destroy) narg->ptrAnnot[isNegEdge(arg)] = NULL;
-				}
-			}
-		}
-	}
-
-	return accum;
-}
-
 Edge generateBinaryConstraint(CNF *cnf, uint numvars, Edge *vars, uint value) {
 	Edge carray[numvars];
 	for (uint j = 0; j < numvars; j++) {
diff --git a/src/Backend/constraint.h b/src/Backend/constraint.h
index 0683230..a48e5da 100644
--- a/src/Backend/constraint.h
+++ b/src/Backend/constraint.h
@@ -30,59 +30,26 @@ enum NodeType {
 
 typedef enum NodeType NodeType;
 
-struct NodeFlags {
-	NodeType type : 2;
-	int varForced : 1;
-	int wasExpanded : 2;
-	int cnfVisitedDown : 2;
-	int cnfVisitedUp : 2;
-};
-
-typedef struct NodeFlags NodeFlags;
-
 struct Node {
-	NodeFlags flags;
 	uint numEdges;
-	uint hashCode;
-	uint intAnnot[2];
-	void *ptrAnnot[2];
+	NodeType type;
 	Edge edges[];
 };
 
-#define DEFAULT_CNF_ARRAY_SIZE 64
-#define LOAD_FACTOR 0.25
+typedef struct Node Node;
 
 struct CNF {
 	uint varcount;
-	uint capacity;
-	uint size;
-	uint mask;
-	uint maxsize;
-	bool enableMatching;
-	Node **node_array;
 	IncrementalSolver *solver;
-	VectorEdge constraints;
-	VectorEdge args;
 	long long solveTime;
 	long long encodeTime;
 };
 
 typedef struct CNF CNF;
 
-struct CNFExpr;
-typedef struct CNFExpr CNFExpr;
-
-static inline bool getExpanded(Node *n, int isNegated) {
-	return n->flags.wasExpanded & (1 << isNegated);
-}
-
-static inline void setExpanded(Node *n, int isNegated) {
-	n->flags.wasExpanded |= (1 << isNegated);
-}
-
 static inline Edge constraintNegate(Edge e) {
-	Edge enew = { (Node *) (((uintptr_t) e.node_ptr) ^ NEGATE_EDGE)};
-	return enew;
+	Edge eneg = { (Node *) (((uintptr_t) e.node_ptr) ^ NEGATE_EDGE)};
+	return eneg;
 }
 
 static inline bool sameNodeVarEdge(Edge e1, Edge e2) {
@@ -119,7 +86,7 @@ static inline Node *getNodePtrFromEdge(Edge e) {
 
 static inline NodeType getNodeType(Edge e) {
 	Node *n = getNodePtrFromEdge(e);
-	return n->flags.type;
+	return n->type;
 }
 
 static inline bool equalsEdge(Edge e1, Edge e2) {
@@ -167,20 +134,12 @@ static inline Literal getEdgeVar(Edge e) {
 	return isNegEdge(e) ? -val : val;
 }
 
-static inline bool isProxy(CNFExpr *expr) {
-	return (bool) (((intptr_t) expr) & 1);
-}
-
-static inline Literal getProxy(CNFExpr *expr) {
-	return (Literal) (((intptr_t) expr) >> 1);
-}
-
 CNF *createCNF();
 void deleteCNF(CNF *cnf);
 void resetCNF(CNF *cnf);
 
 uint hashNode(NodeType type, uint numEdges, Edge *edges);
-Node *allocNode(NodeType type, uint numEdges, Edge *edges, uint hashCode);
+Node *allocNode(NodeType type, uint numEdges, Edge *edges);
 bool compareNodes(Node *node, NodeType type, uint numEdges, Edge *edges);
 Edge create(CNF *cnf, NodeType type, uint numEdges, Edge *edges);
 Edge constraintOR(CNF *cnf, uint numEdges, Edge *edges);
@@ -199,17 +158,6 @@ int solveCNF(CNF *cnf);
 bool getValueCNF(CNF *cnf, Edge var);
 void printCNF(Edge e);
 
-void convertPass(CNF *cnf, bool backtrackLit);
-void convertConstraint(CNF *cnf, VectorEdge *stack, Edge e, bool backtrackLit);
-void constrainCNF(CNF *cnf, Literal l, CNFExpr *exp);
-void produceCNF(CNF *cnf, Edge e);
-CNFExpr *produceConjunction(CNF *cnf, Edge e);
-CNFExpr *produceDisjunction(CNF *cnf, Edge e);
-bool propagate(CNF *cnf, CNFExpr **dest, CNFExpr *src, bool negate);
-void saveCNF(CNF *cnf, CNFExpr *exp, Edge e, bool sign);
-CNFExpr *fillArgs(CNF *cnf, Edge e, bool isNeg, Edge *largestEdge);
-Literal introProxy(CNF *cnf, Edge e, CNFExpr *exp, bool isNeg);
-void outputCNF(CNF *cnf, CNFExpr *expr);
 
 Edge generateBinaryConstraint(CNF *cnf, uint numvars, Edge *vars, uint value);
 Edge generateLTValueConstraint(CNF *cnf, uint numvars, Edge *vars, uint value);