let f be U-continuous Function; :: thesis: ( dom f is subset-closed implies Trace f c= graph f )
assume A1: dom f is subset-closed ; :: thesis: Trace f c= graph f
let x, z be object ; :: according to RELAT_1:def 3 :: thesis: ( not [x,z] in Trace f or [x,z] in graph f )
assume [x,z] in Trace f ; :: thesis: [x,z] in graph f
then consider a, y being set such that
A2: [x,z] = [a,y] and
A3: a in dom f and
A4: y in f . a and
A5: for b being set st b in dom f & b c= a & y in f . b holds
a = b by Def17;
consider b being set such that
A6: b is finite and
A7: b c= a and
A8: y in f . b by A1, A3, A4, Th21;
b in dom f by A1, A3, A7;
then a = b by A5, A7, A8;
hence [x,z] in graph f by A2, A3, A4, A6, Th24; :: thesis: verum