let S be non empty non void ManySortedSign ; :: thesis: for X being V5() ManySortedSet of
for s1, s2 being SortSymbol of S st s1 <> s2 holds
(FreeSort X) . s1 misses (FreeSort X) . s2
let X be V5() ManySortedSet of ; :: thesis: for s1, s2 being SortSymbol of S st s1 <> s2 holds
(FreeSort X) . s1 misses (FreeSort X) . s2
let s1, s2 be SortSymbol of S; :: thesis: ( s1 <> s2 implies (FreeSort X) . s1 misses (FreeSort X) . s2 )
assume that
A1:
s1 <> s2
and
A2:
((FreeSort X) . s1) /\ ((FreeSort X) . s2) <> {}
; :: according to XBOOLE_0:def 7 :: thesis: contradiction
consider x being set such that
A3:
x in ((FreeSort X) . s1) /\ ((FreeSort X) . s2)
by A2, XBOOLE_0:def 1;
A4:
( x in (FreeSort X) . s1 & x in (FreeSort X) . s2 )
by A3, XBOOLE_0:def 4;
A5:
( (FreeSort X) . s1 = FreeSort X,s1 & (FreeSort X) . s2 = FreeSort X,s2 )
by Def13;
set D = DTConMSA X;
consider a being Element of TS (DTConMSA X) such that
A6:
a = x
and
A7:
( ex x1 being set st
( x1 in X . s1 & a = root-tree [x1,s1] ) or ex o1 being OperSymbol of S st
( [o1,the carrier of S] = a . {} & the_result_sort_of o1 = s1 ) )
by A4, A5;
consider b being Element of TS (DTConMSA X) such that
A8:
b = x
and
A9:
( ex x2 being set st
( x2 in X . s2 & b = root-tree [x2,s2] ) or ex o2 being OperSymbol of S st
( [o2,the carrier of S] = b . {} & the_result_sort_of o2 = s2 ) )
by A4, A5;