let G be _Graph; rng H3(G) misses rng H4(G)
assume
rng H3(G) meets rng H4(G)
; contradiction
then consider z being object such that
A1:
( z in rng H3(G) & z in rng H4(G) )
by XBOOLE_0:3;
consider z0 being object such that
A2:
( z0 in dom H3(G) & H3(G) . z0 = z )
by A1, FUNCT_1:def 3;
consider z1 being object such that
A3:
( z1 in dom H4(G) & H4(G) . z1 = z )
by A1, FUNCT_1:def 3;
z0 in [:(the_Edges_of G),{0}:]
by A2, Lm5;
then consider x0, y0 being object such that
A4:
( x0 in the_Edges_of G & y0 in {0} & z0 = [x0,y0] )
by ZFMISC_1:def 2;
z1 in [:(the_Edges_of G),{1}:]
by A3, Lm5;
then consider x1, y1 being object such that
A5:
( x1 in the_Edges_of G & y1 in {1} & z1 = [x1,y1] )
by ZFMISC_1:def 2;
A6:
( x0 in dom H1(G) & y0 in dom (id {0}) )
by A4, Lm4;
A7:
( x1 in dom H2(G) & y1 in dom (id {1}) )
by A5, Lm4;
A8: [(H1(G) . x0),((id {0}) . y0)] =
H3(G) . (x0,y0)
by A6, FUNCT_3:def 8
.=
z
by A2, A4, BINOP_1:def 1
.=
H4(G) . (x1,y1)
by A3, A5, BINOP_1:def 1
.=
[(H2(G) . x1),((id {1}) . y1)]
by A7, FUNCT_3:def 8
;
A9:
( y0 = 0 & y1 = 1 )
by A4, A5, TARSKI:def 1;
then 0 =
(id {0}) . y0
by A4, FUNCT_1:18
.=
(id {1}) . y1
by A8, XTUPLE_0:1
.=
1
by A5, A9, FUNCT_1:18
;
hence
contradiction
; verum