Sindbad~EG File Manager

Length of proof is 6.  Level of proof is 4.

---------------- PROOF ----------------

21 [] T(x,y,y).
24 [] -T(xa,xb,xc)| -T(xb,xa,xc)|xa=xb.
110 [] -opposite(xa,xp,xq,xb)| -Col(xp,xq,xb).
111 [] -opposite(xa,xp,xq,xb)|T(xa,il(xa,xb,xp,xq),xb).
112 [] -opposite(xa,xp,xq,xb)|Col(xp,xq,il(xa,xb,xp,xq)).
129 [] -opposite(xa,xp,xq,xc)|opposite(xb,xp,xq,xc)| -samesideline(xa,xb,xp,xq).
136 [] opposite(a,p,q,b).
137 [] samesideline(a,b,p,q).
142 [binary,136.1,110.1] -Col(p,q,b).
154 [hyper,129,136,137] opposite(b,p,q,b).
171 [binary,154.1,112.1] Col(p,q,il(b,b,p,q)).
172 [binary,154.1,111.1] T(b,il(b,b,p,q),b).
194 [binary,172.1,24.2,unit_del,21] il(b,b,p,q)=b.
243 [para_from,194.1.1,171.1.3] Col(p,q,b).
244 [binary,243.1,142.1] $F.