diff --git a/pv.c b/pv.c
index 53937eb..8c1ec67 100644
--- a/pv.c
+++ b/pv.c
@@ -85,7 +85,7 @@ static I jtdcase(J jt,I xi,V*v){
 /* 5   s  f  t  */
 
 TACT(jtvdyad){A fs,sf,xt,yt;B xl,xr,yl,yr;I xi=-1,yi=-1;TA x,y,z={one};V*u=0,*v=0;
- fs=stack[e-1].a; x=stack[b]; y=stack[e]; sf=swapc(fs);
+ fs=stack[e-1].a; x=stack[b]; y=stack[e]; sf=swap(fs);
  if(xt=tine(x.t)){xi=tvi(x.t); u=VAV(xt); if(0>xi&&CFORK==u->id){xi=tvi(u->f); if(0>xi)xi=tvi(u->h);}}
  if(yt=tine(y.t)){yi=tvi(y.t); v=VAV(yt); if(0>yi&&CFORK==v->id){yi=tvi(v->f); if(0>yi)yi=tvi(v->h);}}
  if(fs==ds(CLEFT)){if(xt)z.t=xt; else z.a=x.a; R z;}
diff --git a/vz.c b/vz.c
index 74b6b97..95ab337 100644
--- a/vz.c
+++ b/vz.c
@@ -92,10 +92,13 @@ ZF2(jtzrem){D a,b,d;Z q;
  R zminus(v,ztymes(u,q));
 }
 
-ZF2(jtzgcd){D a,b;Z t,z;
+ZF2(jtzgcd){D a,b,d;Z q,t,z;
  ZASSERT(!(ZINF(u)||ZINF(v)),EVNAN);
  while(ZNZ(u)){
-  t=zrem(u,v); if(t.re>v.re/2)t.re-=v.re; if(t.im>v.im/2)t.im-=v.im;
+  d=u.re*u.re+u.im*u.im;
+  a=u.re*v.re+u.im*v.im; q.re=tfloor(0.5+a/d);
+  b=u.re*v.im-u.im*v.re; q.im=tfloor(0.5+b/d);
+  t=zminus(v,ztymes(u,q));
   v.re=u.re; v.im=u.im; u.re=t.re; u.im=t.im;
  }
  z.re=a=v.re; z.im=b=v.im;