--- extensions/adj2d/adj2D.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/adj2d/adj2D.h	2018-08-29 20:03:25.109519358 -0600
@@ -25,7 +25,7 @@ Word ADJ_2D1P2(Word U, Word V, Word w_l,
 Word ADJ_2D1P3(Word U, Word w_l, Word B);
 Word ADJ_2D1_COMPLETE(Word c, Word c_l, Word c_r, Word P, Word J);
 Word ADJ_2D1_SIMPLE(Word U, Word V, Word w_l, Word B);
-Word CWD_VECTOR_Q(Word u, Word v);
+Word CWD_VECTOR_Q(Word u, Word v) __pure;
 Word EQUAL_ON_ONES(Word u, Word v);
 Word LDCOEFMASK(Word c, Word P, Word J);
 Word LDCOEFMASK(Word c, Word P, Word J);
@@ -34,13 +34,13 @@ Word P1(Word U, Word V, Word W, Word v_l
 Word P2(Word x_l, Word x_r, Word U, Word V, Word W, Word v_l, Word B);
 Word P3(Word U, Word V, Word W, Word v_l, Word B);
 Word P4(Word U, Word V, Word W, Word v_l, Word B);
-Word SUM_NORM_SP(Word v);
+Word SUM_NORM_SP(Word v) __pure;
 Word VECTOR_DIF(Word u, Word v);
 Word VECTOR_DIF_S(Word u, Word v, Word *f);
-Word VECTOR_LTEQ(Word u, Word v);
+Word VECTOR_LTEQ(Word u, Word v) __pure;
 Word VECTOR_NEG(Word u);
-Word VECTOR_ODD_E(Word v_);
-Word VECTOR_SEMI_COMP(Word u, Word v);
+Word VECTOR_ODD_E(Word v_) __pure;
+Word VECTOR_SEMI_COMP(Word u, Word v) __pure;
 Word VECTOR_SUM(Word u, Word v);
 Word VECTOR_S_PROD(Word s, Word v);
 Word ZERO_VECTOR(Word n);
@@ -55,7 +55,7 @@ Word RIIFACMA(Word I, Word A, Word t, Wo
 Word  RIIFACMABR(Word P, Word J, Word K, Word *H, Word *I);
 Word SPRLC(Word c);
 Word ADJ2DITOEL(Word L, Word c1, Word c0);
-Word CCTV(Word C);
+Word CCTV(Word C) __pure;
 void CTVPROPUP(Word C, Word t, Word N, Word by);
 void TVCLOSURE1D(Word D, Word P, Word J, Word k, Word t);
 void TVCLOSURE1DS(Word D, Word P, Word J, Word k, Word t);
--- extensions/adj2d/truthbytop/truthbytop.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/adj2d/truthbytop/truthbytop.h	2018-08-29 20:03:25.109519358 -0600
@@ -4,13 +4,13 @@
 #include "adj2D.h"
 
 void GADDVERTEX(Word v, Word l, Word *G_);
-Word GSTACKHANDLE(Word i, Word G_);
+Word GSTACKHANDLE(Word i, Word G_) __pure;
 Word GVERTEXHANDLE(Word v, Word G_);
 Word GVERTEXLABEL(Word v, Word G_);
 void GNEWLABEL(Word v, Word l, Word G_);
 void GADDEDGE(Word e, Word G_);
 Word GSUCCLIST(Word v, Word G_);
-Word vert2dim(Word v);
+Word vert2dim(Word v) __pure;
 Word GPREDLIST(Word v, Word G_);
 
 #endif
--- extensions/newadj/HATEST.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/newadj/HATEST.c	2018-08-29 20:03:25.111519356 -0600
@@ -1,5 +1,5 @@
 #include "newadj2D.h"
-Word ISSECTOR(Word C) { return LAST(LELTI(C,INDX)) % 2; }
+static Word __pure ISSECTOR(Word C) { return LAST(LELTI(C,INDX)) % 2; }
 void SAMPLECWR(Word c);
 void strippedAFLWR(Word M,Word I,Word N,Word a,Word A);
 void ANDWRITExx(Word M,Word I,Word n);
--- extensions/rend/Rend_Cell.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/rend/Rend_Cell.h	2018-08-29 20:03:25.108519359 -0600
@@ -49,8 +49,8 @@ public:
   Rend_Cell& operator[](int i); /* gives child from index   */
   Rend_Cell* neighbor_l(); /* returns left neighbor cell    */
   Rend_Cell* neighbor_r(); /* returns right neighbor cell   */
-  int array_index();       /* returns i such that 
-			      parent->child[i] is the cell  */
+  int array_index() __pure; /* returns i such that 
+				parent->child[i] is the cell  */
   void set_extents(Word J);
   void out_descrip(Rend_Win &W, ostream &out, Mapper &M);
   void out_descrip_ps(Rend_Win &W, ostream &out, Mapper &M);
--- extensions/rend/rend.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/rend/rend.h	2018-08-29 20:03:25.108519359 -0600
@@ -34,7 +34,7 @@ extern "C" {
 
 #include <iostream>
 #include <sstream>
-istream& qein(); // fetches the current qepcad istream object
+istream& qein() __pure; // fetches the current qepcad istream object
 
 class singlelinestream : public istringstream
 {
--- extensions/sfext/addpol/MINPFSETNSC.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/addpol/MINPFSETNSC.c	2018-08-29 20:03:25.110519357 -0600
@@ -25,6 +25,8 @@ outputs
 #define BDCOMP(a,b)       ((a) > (b) ? 1 : ((a) < (b) ? -1 : 0))
 #define CFLCT 5
 
+static Word comp1(Word a, Word b) __pure;
+
 static Word comp1(Word a,Word b) {
   Word A,B,t;
   A = RED(a); B = RED(b); t = 0;
--- extensions/sfext/extlang/CLOSESTINDEX.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/extlang/CLOSESTINDEX.c	2018-08-29 20:03:25.109519358 -0600
@@ -10,6 +10,8 @@ cp: the ESCAD cell in L with index close
 
 #include "extlang.h"
 
+static Word comp(Word u, Word v) __pure;
+
 static Word comp(Word u, Word v)
 {
   Word r,t,U,V,A,B,a,b;
--- extensions/sfext/minhit/MINHITSETSRDR.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/minhit/MINHITSETSRDR.c	2018-08-29 20:03:25.109519358 -0600
@@ -24,6 +24,8 @@ Note:  The point is that not only sortin
 #define BDCOMP(a,b)  ((a) > (b) ? 1 : ((a) < (b) ? -1 : 0))
 #define MC_FAIL 0
 
+static Word comp(Word a, Word b) __pure;
+
 static Word comp(Word a, Word b) {
       Word ap,bp,t,q;
       ap = a; bp = b;
--- extensions/sfext/mysort.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/mysort.h	2018-08-29 20:03:25.110519357 -0600
@@ -52,7 +52,7 @@ Side Effects
 Word GMSDS(Word *A, Word m, Word (*C)(Word,Word));
 
 
-extern Word BVC(Word *u_,Word *v_,Word n);
+extern Word BVC(const Word *u_,const Word *v_,Word n) __pure;
 extern void BVIS(Word **A,Word m,Word n);
-extern Word BVCI1(Word *u_,Word *v_,Word n);
+extern Word BVCI1(const Word *u_,const Word *v_,Word n) __pure;
 extern void BVISI1(Word **A,Word m,Word n);
--- extensions/sfext/sfcons/ESPCADDOPFSUFF.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/sfcons/ESPCADDOPFSUFF.c	2018-08-29 20:03:25.110519357 -0600
@@ -17,7 +17,7 @@ outputs
 #include "qepcad.h"
 #include "espcad.h"
 
-static Word comp(Word A, Word B);
+static Word comp(Word A, Word B) __pure;
 #define BDCOMP(a,b)   ((a) > (b) ? 1 : ((a) < (b) ? -1 : 0))
 	  
 Word ESPCADDOPFSUFF(Word P, Word K)
--- extensions/sfext/sort/BVC.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/sort/BVC.c	2018-08-29 20:03:25.110519357 -0600
@@ -12,9 +12,9 @@ b : -1 if u < v in lex order, 0 if u = v
   ======================================================================*/
 #include "mysort.h"
 
-Word BVC(Word *u_, Word *v_, Word n)
+Word BVC(const Word *u_, const Word *v_, Word n)
 {
-       Word *w,*u,*v;
+       const Word *w,*u,*v;
        u = u_;
        v = v_;
        w = u + n;
--- extensions/sfext/sort/BVCI1.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ extensions/sfext/sort/BVCI1.c	2018-08-29 20:03:25.110519357 -0600
@@ -12,9 +12,9 @@ b : -1 if u < v in lex order, 0 if u = v
   ======================================================================*/
 #include "qepcad.h"
 
-Word BVCI1(Word *u_, Word *v_, Word n)
+Word BVCI1(const Word *u_, const Word *v_, Word n)
 {
-       Word *w,*u,*v;
+       const Word *w,*u,*v;
        u = u_+1;
        v = v_+1;
        w = u + n;
--- source/main/qepcadcls.h.orig	2018-03-16 14:22:00.000000000 -0600
+++ source/main/qepcadcls.h	2018-08-29 20:03:25.111519356 -0600
@@ -221,7 +221,7 @@ UnsatCore UNSATCORE;
   void CHCELL(Word cs, Word *c_, Word *t_);
   void ECLI(Word D, Word *c_, Word *t_);
   BDigit SCREEN(Word c); 
-  BDigit SCREENBYQUANTIFIER(Word c); 
+  BDigit SCREENBYQUANTIFIER(Word c) __pure; 
   Word ISFECLI(Word D);
   Word INITPCAD();
   void EVALUATE(Word c, Word k, Word F, Word A);
--- source/qepcad.h.orig	2018-01-25 14:25:22.000000000 -0700
+++ source/qepcad.h	2018-08-29 20:04:27.596451754 -0600
@@ -134,10 +134,10 @@ void IPLLDWRMOD(Word V, Word A);
 void IPLSRP(Word A, Word *s_, Word *P_);
 Word IPRESPRS(Word r, Word A, Word B);
 Word IPRNEVAL(BDigit r, Word P, BDigit t, Word b);
-Word ISATOMF(Word F);
+Word ISATOMF(Word F) __pure;
 Word ISDESIRED(Word c, Word C);
 Word ISNULL(Word L);
-Word ISPRIMIT(Word s);
+Word ISPRIMIT(Word s) __pure;
 void IUPRWR(Word v, Word A, Word I);
 Word IXCOMP(Word c1, Word c2);
 void LABELWR(Word N, Word I);
@@ -148,7 +148,7 @@ Word LOAR(Word k, Word Q, Word F);
 Word LPFTOLRLP(Word r, Word L);
 Word LPFZCALL(Word c, Word P, Word D);
 Word LUNION(Word L1, Word L2);
-Word LVCOMP(Word c1, Word c2);
+Word LVCOMP(Word c1, Word c2) __pure;
 Word MAFDIF(Word p,Word a,Word b);
 Word MAFHOM(Word p,Word M,Word a);
 Word MAFINV(Word p,Word M,Word a);
@@ -158,7 +158,7 @@ Word MAFUPEPROD(Word p,Word M,Word a,Wor
 Word MAFUPGCD(Word p,Word M,Word A,Word B);
 Word MAFUPMON(Word p, Word M, Word A);
 Word MAFUPNR(Word p, Word M, Word A, Word B);
-Word MATCHWORD(Word A, Word B);
+Word MATCHWORD(Word A, Word B) __pure;
 Word MBPROD(Word A, Word B);
 Word MCELL(Word a1, Word a2, Word a3, Word a4, Word a5, Word a6, Word a7, Word a8, Word a9, Word a10);
 Word MKMUL(Word E, Word k);
@@ -169,7 +169,7 @@ Word MPOLY(Word a1, Word a2, Word a3, Wo
 Word MUPNR(Word p,Word A,Word B);
 Word MVLMA(Word H_t, Word H_f);
 Word MVLMASF(Word H_t, Word H_f);
-Word NEGRLOP(Word T);
+Word NEGRLOP(Word T) __constfunc;
 void NEXTCELL(Word D, Word c, Word *cp_, Word *t_);
 void NEXTCOMB(Word n, Word r, Word Rs, Word *R_, Word *q_);
 void NEXTLEXI(Word l, Word Rs, Word *R_, Word *q_);
@@ -188,12 +188,12 @@ void PARENTWR(Word P);
 void PCADWR(Word c);
 void PCADSWR(Word c);
 Word PFCOICQ(Word r, Word A, Word c, Word P, Word D);
-Word PFPRDQ(Word P);
+Word PFPRDQ(Word P) __pure;
 void PIMPTBLWR(Word C, Word R, Word V);
 void PLABELWR(Word P);
 Word PLDEG(Word P);
 Word PLPOS(Word P, Word i);
-Word PPPRDQ(Word P);
+Word PPPRDQ(Word P) __pure;
 void PQFF(Word F, Word L, Word *Lp_);
 void PRDADJINFO();
 void PRDCC();
@@ -209,7 +209,7 @@ void PRLDB();
 void PRODWR(Word v);
 void PROMPT();
 //void PROPAGATE(Word D, Word c, Word k, Word f, Word Q);
-void PRQUIT();
+void PRQUIT() __noreturn;
 void PRTRACEA();
 void PRTRACED();
 void PRUDB();
@@ -217,7 +217,7 @@ void PRWHATIS();
 void PSIGTBL(Word c, Word f, Word T_t, Word T_f, Word *Tp_t_, Word *Tp_f_);
 void PSIMREP(Word r, Word P, Word *rs_, Word *Ps_);
 void QEGLOBALS();
-const char* QEPCADBVersion();
+const char* QEPCADBVersion() __constfunc;
 Word QFFFSOP(Word H, Word P, Word f);
 void QFFLPWR(Word N, Word V, Word F);
 void QFFLWR(Word N, Word V, Word F);
@@ -239,7 +239,7 @@ Word RMMPF(Word P, Word k);
 Word RMMPJ(Word J, Word k);
 Word RMNOTOP(Word F);
 Word RMNOTOPN(Word F);
-Word RNFAF(Word a);
+Word RNFAF(Word a) __pure;
 Word RVSPTSVSP(BDigit r, Word P, BDigit s);
 void SALGF(Word f, Word F, Word *G_, Word *H_);
 void SAMPLEWR(Word r, Word s, Word PCNUMDEC);
@@ -263,7 +263,7 @@ Word SOPFST(Word T);
 Word SOSRSUBS(Word L);
 Word SOSRSUPS(Word L);
 void SPFRPSFT(Word P, Word c, Word k, Word *R_, Word *F_);
-Word SSCOMP(Word c1, Word c2);
+Word SSCOMP(Word c1, Word c2) __pure;
 Word STACKMULT(Word C);
 void STACKMWR(Word M);
 Word STFSOP(Word H);
@@ -631,9 +631,9 @@ Word NEWDERIV(Word KT, Word P, Word Pb,
 void STRIPPED_BIGLOOP(Word Jb, Word Pb, Word P0, Word D0, Word N, Word *P_, Word *D_);
 Word CADSCL(Word C, Word i);
 Word CELLFINDEX(Word D, Word I);
-Word CRCELL(Word d);
+Word CRCELL(Word d) __pure;
 void CSN(Word c, Word D, Word *b_, Word *d_);
-Word BZWAZ(Word a, Word b);
+Word BZWAZ(Word a, Word b) __pure;
 void LISTOFCWTV(Word C, Word *Lt_, Word *Lf_);
 BDigit NUMSOLPOINTS(Word D, BDigit k);
 Word LPFOWCS(Word C, Word B, Word P);
@@ -670,7 +670,7 @@ void LTFOCWTVMARK(Word C, Word *Lt_, Wor
 Word OPARTLIST(Word n);
 Word PARTLIST(Word n);
 Word SCAD2ESCAD(Word P, Word Ps, Word Ds, Word A);
-Word SCCONFLICTQ(Word L1, Word L2);
+Word SCCONFLICTQ(Word L1, Word L2) __pure;
 Word SCFILTER(Word c, Word d);
 void SETCADTV2MARK(Word D);
 void SETMARK2FMA(Word D, Word F, Word P);
@@ -694,7 +694,7 @@ void CSORTSS(Word **A, Word a, Word L);
 Word ICSIGDIFFL(Word **A, Word a, Word k);
 Word MINPFSET(Word P, Word S, Word D, Word N);
 Word PWUDSCWCP(Word D, Word P, Word N);
-Word SIGEQUALOL(Word *A, Word *B, Word L);
+Word SIGEQUALOL(Word *A, Word *B, Word L) __pure;
 void TDTOD(Word P, Word N, Word ***P2_, Word *P1_, Word *k_);
 Word FMA2DNF(Word F);
 Word FMA2QUNF(Word F, Word P);
@@ -706,8 +706,8 @@ Word FMADMQ(Word F,Word C,Word k,Word P)
 Word singleFMADMQ(Word F,Word C,Word k,Word P);
 void FMAIWRITE(Word F);
 Word FMALEVEL(Word F);
-Word FMAOPCOMBINE(Word F);
-Word FMAQEXTAF(Word F) ;
+Word FMAOPCOMBINE(Word F) __pure;
+Word FMAQEXTAF(Word F) __pure;
 Word FMAPOLLIST(Word F, Word P);
 void FMAREAD(Word P,Word V, Word *F_,Word *t_);
 Word FMASMOOTH(Word F);
@@ -724,9 +724,9 @@ void FMAWRITENEWLINEp(Word F, Word P, Wo
 void FMAWRITEQEIN(Word F, Word P, Word V);
 void FMAWRITEp(Word F, Word P, Word V, Word flag);
 Word FMA_REMCONST(Word F);
-Word FTYPEINFO(Word A);
+Word FTYPEINFO(Word A) __pure;
 void IPDWRITELATEX(Word r, Word A, Word V);
-Word POLINDEX2SIGINDEX(Word P_i, Word j);
+Word POLINDEX2SIGINDEX(Word P_i, Word j) __pure;
 void SETTV2FMA(Word D, Word P, Word F, Word k);
 void SETORDERfromFMA(Word D,Word P,Word F,Word o);
 void SETORDER(Word D,Word P,Word V);
@@ -740,7 +740,7 @@ Word RSFHSP(Word A, Word *Ab_);
 Word CADCL(Word C, Word i);
 Word CADFPCAD(Word D, Word P, Word S, Word I, Word Pb);
 Word CADFPCADWI(Word D, Word P, Word S, Word I, Word Pb);
-Word CATV(Word c);
+Word CATV(Word c) __pure;
 void CCADCON(Word n, Word P, Word C, Word *Ps_, Word *Cs_);
 void CCADCONEXT(Word n, Word P, Word C, Word *Ps_, Word *Cs_, Word *N_);
 void CCADCONFPFS(Word n, Word P, Word C, Word N, Word *Ps_, Word *Cs_);
@@ -750,7 +750,7 @@ Word CHTVQ(Word cs, Word b);
 Word CTSEQ(Word as, Word bs);
 void LTFOCALWTV(Word C, Word n, Word *Lt_, Word *Lf_);
 void LTFOCWTV(Word C, Word *Lt_, Word *Lf_);
-Word PCADCFCADC(Word c, Word Cs);
+Word PCADCFCADC(Word c, Word Cs) __pure;
 Word PCADCINDEX(Word c);
 Word PCADCL(Word Cs, Word i);
 Word PCADCSV(Word cs, Word Ps);
@@ -793,7 +793,7 @@ Word DOPFSUFF(Word P, Word K);
 Word ESPCADDOPFSUFF(Word P, Word K);
 Word GEOPARTII(Word F, Word S, Word P, Word Fs);
 Word GEODATA(Word c, Word A, Word P);
-Word GEOHEURISTIC(Word a, Word b);
+Word GEOHEURISTIC(Word a, Word b) __pure;
 Word GEOMERGE(Word c,Word G,Word P);
 Word GEOFIT(Word c,Word G,Word P);
 Word ATOMFILTER(Word L_A,Word L_C,Word P);
@@ -821,7 +821,7 @@ Word NECCONDS(Word L_T, Word L_F, Word L
 Word DOPFSUFF_FULLD(Word P, Word K);
 Word ESPCADDOPFSUFF_FULLD(Word P, Word K);
 Word BVC(Word *u_, Word *v_, Word n);
-Word BVCI1(Word *u_, Word *v_, Word n);
+Word BVCI1(Word *u_, Word *v_, Word n) __pure;
 void BVIS(Word **A, Word m, Word n);
 void BVISI1(Word **A, Word m, Word n);
 void GIS(Word *A, Word m, Word (*C)(Word,Word));
--- source/ticad/QFFTEV.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ source/ticad/QFFTEV.c	2018-08-29 20:03:25.112519355 -0600
@@ -12,7 +12,7 @@ Quantifier-Free Formula Trial Evaluation
  \parm{t} is the trial truth value of $F$ on the cell $c$.
 ======================================================================*/
 #include "qepcad.h"
-static Word zeroQ(Word s, Word I_L);
+static Word zeroQ(Word s, Word I_L) __pure;
 static Word ATOMETFEVAL(Word Q, Word D, Word c, Word F);
 
 Word QepcadCls::QFFTEV(Word F, Word c, Word k)
--- source/userint/PRQUIT.c.orig	2018-01-25 14:25:22.000000000 -0700
+++ source/userint/PRQUIT.c	2018-08-29 20:03:25.112519355 -0600
@@ -13,7 +13,4 @@ Step1: /* Process. */
        ENDQEPCAD();
        ENDSACLIB(SAC_FREEMEM);
        exit(0);
-
-Return: /* Prepare for return. */
-       return;
 }