let C1, C2 be Category; for F being Functor of C1,C2
for a, b, c being Object of C1
for f, g being Morphism of C1 st f in Hom a,b & g in Hom b,c holds
for x being Element of Args (compsym a,b,c),(MSAlg C1) st x = <*g,f*> holds
for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*>
let F be Functor of C1,C2; for a, b, c being Object of C1
for f, g being Morphism of C1 st f in Hom a,b & g in Hom b,c holds
for x being Element of Args (compsym a,b,c),(MSAlg C1) st x = <*g,f*> holds
for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*>
set CS1 = CatSign the carrier of C1;
set CS2 = CatSign the carrier of C2;
set A1 = MSAlg C1;
set A2 = MSAlg C2;
set u = Upsilon F;
set p = Psi F;
set B = (MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F);
let a, b, c be Object of C1; for f, g being Morphism of C1 st f in Hom a,b & g in Hom b,c holds
for x being Element of Args (compsym a,b,c),(MSAlg C1) st x = <*g,f*> holds
for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*>
set o = compsym a,b,c;
let f, g be Morphism of C1; ( f in Hom a,b & g in Hom b,c implies for x being Element of Args (compsym a,b,c),(MSAlg C1) st x = <*g,f*> holds
for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*> )
assume that
A1:
f in Hom a,b
and
A2:
g in Hom b,c
; for x being Element of Args (compsym a,b,c),(MSAlg C1) st x = <*g,f*> holds
for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*>
let x be Element of Args (compsym a,b,c),(MSAlg C1); ( x = <*g,f*> implies for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*> )
assume A3:
x = <*g,f*>
; for H being ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) st H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) holds
H # x = <*(F . g),(F . f)*>
F . g in Hom (F . b),(F . c)
by A2, CAT_1:123;
then A4:
( dom (F . g) = F . b & cod (F . g) = F . c )
by CAT_1:18;
F . f in Hom (F . a),(F . b)
by A1, CAT_1:123;
then
( dom (F . f) = F . a & cod (F . f) = F . b )
by CAT_1:18;
then A5:
<*(F . g),(F . f)*> in Args (compsym (F . a),(F . b),(F . c)),(MSAlg C2)
by A4, Th39;
A6:
( dom g = b & cod g = c )
by A2, CAT_1:18;
( dom f = a & cod f = b )
by A1, CAT_1:18;
then A7:
x in Args (compsym a,b,c),(MSAlg C1)
by A3, A6, Th39;
let H be ManySortedFunction of (MSAlg C1),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)); ( H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1) implies H # x = <*(F . g),(F . f)*> )
assume A8:
H = F -MSF the carrier of (CatSign the carrier of C1),the Sorts of (MSAlg C1)
; H # x = <*(F . g),(F . f)*>
the Sorts of (MSAlg C1) . (homsym b,c) = Hom b,c
by Def15;
then
H . (homsym b,c) = F | (Hom b,c)
by A8, Def1;
then A9:
(H . (homsym b,c)) . g = F . g
by A2, FUNCT_1:72;
A10:
dom <*g,f*> = Seg 2
by FINSEQ_3:29;
then A11:
1 in dom <*g,f*>
by FINSEQ_1:4, TARSKI:def 2;
the Sorts of (MSAlg C1) . (homsym a,b) = Hom a,b
by Def15;
then
H . (homsym a,b) = F | (Hom a,b)
by A8, Def1;
then A12:
(H . (homsym a,b)) . f = F . f
by A1, FUNCT_1:72;
A13:
2 in dom <*g,f*>
by A10, FINSEQ_1:4, TARSKI:def 2;
Upsilon F, Psi F form_morphism_between CatSign the carrier of C1, CatSign the carrier of C2
by Th33;
then A14: Args (compsym a,b,c),((MSAlg C2) | (CatSign the carrier of C1),(Upsilon F),(Psi F)) =
Args ((Psi F) . (compsym a,b,c)),(MSAlg C2)
by INSTALG1:25
.=
Args (compsym (F . a),(F . b),(F . c)),(MSAlg C2)
by Th32
;
then consider g9, f9 being Morphism of C2 such that
A15:
H # x = <*g9,f9*>
and
dom f9 = F . a
and
cod f9 = F . b
and
dom g9 = F . b
and
cod g9 = F . c
by A5, Th39;
A16:
<*g9,f9*> . 1 = g9
by FINSEQ_1:61;
A17:
the_arity_of (compsym a,b,c) = <*(homsym b,c),(homsym a,b)*>
by Def5;
then
( <*g,f*> . 1 = g & (the_arity_of (compsym a,b,c)) /. 1 = homsym b,c )
by FINSEQ_1:61, FINSEQ_4:26;
then A18:
<*g9,f9*> . 1 = F . g
by A3, A7, A5, A14, A15, A9, A11, MSUALG_3:24;
( <*g,f*> . 2 = f & (the_arity_of (compsym a,b,c)) /. 2 = homsym a,b )
by A17, FINSEQ_1:61, FINSEQ_4:26;
then
<*g9,f9*> . 2 = F . f
by A3, A7, A5, A14, A15, A12, A13, MSUALG_3:24;
hence
H # x = <*(F . g),(F . f)*>
by A15, A18, A16, FINSEQ_1:61; verum