set a = o,o :-> <^o,o^>;
dom (o,o :-> <^o,o^>) = [:{o},{o}:] by FUNCT_2:def 1;
then reconsider a = o,o :-> <^o,o^> as ManySortedSet of by PARTFUN1:def 4;
set m = [o,o,o] .--> (the Comp of C . o,o,o);
dom ([o,o,o] .--> (the Comp of C . o,o,o)) = {[o,o,o]} by FUNCOP_1:19
.= [:{o},{o},{o}:] by MCART_1:39 ;
then reconsider m = [o,o,o] .--> (the Comp of C . o,o,o) as ManySortedSet of by PARTFUN1:def 4, RELAT_1:def 18;
A1: a . o,o = the Arrows of C . o,o by ALTCAT_1:12;
m is ManySortedFunction of {|a,a|},{|a|}
proof
let i be set ; :: according to PBOOLE:def 18 :: thesis: ( not i in [:{o},{o},{o}:] or m . i is Element of bool [:({|a,a|} . i),({|a|} . i):] )
assume i in [:{o},{o},{o}:] ; :: thesis: m . i is Element of bool [:({|a,a|} . i),({|a|} . i):]
then i in {[o,o,o]} by MCART_1:39;
then A2: i = [o,o,o] by TARSKI:def 1;
A3: o in {o} by TARSKI:def 1;
A4: {|a,a|} . i = {|a,a|} . o,o,o by A2, MULTOP_1:def 1
.= [:(the Arrows of C . o,o),(the Arrows of C . o,o):] by A1, A3, ALTCAT_1:def 6 ;
{|a|} . i = {|a|} . o,o,o by A2, MULTOP_1:def 1
.= the Arrows of C . o,o by A1, A3, ALTCAT_1:def 5 ;
hence m . i is Element of bool [:({|a,a|} . i),({|a|} . i):] by A2, A4, FUNCOP_1:87; :: thesis: verum
end;
then reconsider m = m as BinComp of a ;
set D = AltCatStr(# {o},a,m #);
AltCatStr(# {o},a,m #) is SubCatStr of C
proof
thus the carrier of AltCatStr(# {o},a,m #) c= the carrier of C ; :: according to ALTCAT_2:def 11 :: thesis: ( the Arrows of AltCatStr(# {o},a,m #) cc= the Arrows of C & the Comp of AltCatStr(# {o},a,m #) cc= the Comp of C )
thus the Arrows of AltCatStr(# {o},a,m #) cc= the Arrows of C :: thesis: the Comp of AltCatStr(# {o},a,m #) cc= the Comp of C
proof
thus [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] c= [:the carrier of C,the carrier of C:] ; :: according to ALTCAT_2:def 2 :: thesis: for i being set st i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] holds
the Arrows of AltCatStr(# {o},a,m #) . i c= the Arrows of C . i

let i be set ; :: thesis: ( i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] implies the Arrows of AltCatStr(# {o},a,m #) . i c= the Arrows of C . i )
assume i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] ; :: thesis: the Arrows of AltCatStr(# {o},a,m #) . i c= the Arrows of C . i
then i in {[o,o]} by ZFMISC_1:35;
then i = [o,o] by TARSKI:def 1;
hence the Arrows of AltCatStr(# {o},a,m #) . i c= the Arrows of C . i by A1; :: thesis: verum
end;
thus [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] c= [:the carrier of C,the carrier of C,the carrier of C:] ; :: according to ALTCAT_2:def 2 :: thesis: for i being set st i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] holds
the Comp of AltCatStr(# {o},a,m #) . i c= the Comp of C . i

let i be set ; :: thesis: ( i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] implies the Comp of AltCatStr(# {o},a,m #) . i c= the Comp of C . i )
assume i in [:the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #),the carrier of AltCatStr(# {o},a,m #):] ; :: thesis: the Comp of AltCatStr(# {o},a,m #) . i c= the Comp of C . i
then i in {[o,o,o]} by MCART_1:39;
then A5: i = [o,o,o] by TARSKI:def 1;
then the Comp of AltCatStr(# {o},a,m #) . i = the Comp of C . o,o,o by FUNCOP_1:87
.= the Comp of C . i by A5, MULTOP_1:def 1 ;
hence the Comp of AltCatStr(# {o},a,m #) . i c= the Comp of C . i ; :: thesis: verum
end;
then reconsider D = AltCatStr(# {o},a,m #) as strict SubCatStr of C ;
take D ; :: thesis: ( the carrier of D = {o} & the Arrows of D = o,o :-> <^o,o^> & the Comp of D = [o,o,o] .--> (the Comp of C . o,o,o) )
thus ( the carrier of D = {o} & the Arrows of D = o,o :-> <^o,o^> & the Comp of D = [o,o,o] .--> (the Comp of C . o,o,o) ) ; :: thesis: verum