Sindbad~EG File Manager

Length of proof is 14.  Level of proof is 4.
 
---------------- PROOF ----------------
 
1 [] E(x,y,y,x).
2 [] -E(x,y,z,v)| -E(x,y,z2,v2)|E(z,v,z2,v2).
6 [] -E(x,y,x1,y1)| -E(y,z,y1,z1)| -E(x,v,x1,v1)| -E(y,v,y1,v1)| -T(x,y,z)| -T(x1,y1,z1)|x=y|E(z,v,z1,v1).
8 [] -E(xa,xb,xc,xd)|E(xc,xd,xa,xb).
10 [] -E(xa,xb,xc,xd)|E(xb,xa,xc,xd).
11 [] -E(xa,xb,xc,xd)|E(xa,xb,xd,xc).
12 [] E(xa,xa,xb,xb).
13 [] T(a,b,c).
14 [] T(a1,b1,c1).
15 [] E(a,b,a1,b1).
16 [] E(b,c,b1,c1).
17 [] -E(a,c,a1,c1).
28 [binary,15.1,11.1] E(a,b,b1,a1).
32 [binary,15.1,8.1] E(a1,b1,a,b).
44 [binary,16.1,8.1] E(b1,c1,b,c).
52 [binary,17.1,11.2] -E(a,c,c1,a1).
53 [binary,17.1,10.2] -E(c,a,a1,c1).
55 [binary,17.1,8.2] -E(a1,c1,a,c).
77 [binary,28.1,10.1] E(b,a,b1,a1).
86 [hyper,2,28,1] E(b1,a1,b,a).
192 [binary,52.1,10.2] -E(c,a,c1,a1).
206 [ur,2,1,53] -E(c1,a1,c,a).
256 [hyper,6,15,16,12,77,13,14,unit_del,192] a=b.
276 [para_from,256.1.2,44.1.3] E(b1,c1,a,c).
343 [hyper,6,32,44,12,86,14,13,unit_del,206] a1=b1.
356 [para_from,343.1.1,55.1.1] -E(b1,c1,a,c).
357 [binary,356.1,276.1] $F.