AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) is SubCatStr of C
proof
thus the carrier of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) c= the carrier of C ; :: according to ALTCAT_2:def 11 :: thesis: ( the Arrows of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) cc= the Arrows of C & the Comp of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) cc= the Comp of C )
thus the Arrows of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) cc= the Arrows of C ; :: thesis: the Comp of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) cc= the Comp of C
thus the Comp of AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) cc= the Comp of C ; :: thesis: verum
end;
then reconsider D = AltCatStr(# the carrier of C,the Arrows of C,the Comp of C #) as SubCatStr of C ;
reconsider D = D as non empty full id-inheriting SubCatStr of C by Th34, Th35;
take D ; :: thesis: ( D is full & not D is empty & D is strict )
thus ( D is full & not D is empty & D is strict ) ; :: thesis: verum