:: BVFUNC10 semantic presentation
theorem Th1: :: BVFUNC10:1
Lemma1:
for b1 being non empty set
for b2, b3, b4 being Element of Funcs b1,BOOLEAN holds ((b2 '&' ('not' b3)) 'or' (b3 '&' ('not' b4))) 'or' (b4 '&' ('not' b2)) '<' ((b3 '&' ('not' b2)) 'or' (b4 '&' ('not' b3))) 'or' (b2 '&' ('not' b4))
proof
let c
1 be non
empty set ;
let c
2, c
3, c
4 be
Element of
Funcs c
1,
BOOLEAN ;
let c
5 be
Element of c
1;
:: according to BVFUNC_1:def 15
assume E2:
(((c2 '&' ('not' c3)) 'or' (c3 '&' ('not' c4))) 'or' (c4 '&' ('not' c2))) . c
5 = TRUE
;
E3:
(((c2 '&' ('not' c3)) 'or' (c3 '&' ('not' c4))) 'or' (c4 '&' ('not' c2))) . c
5 =
(((c2 '&' ('not' c3)) 'or' (c3 '&' ('not' c4))) . c5) 'or' ((c4 '&' ('not' c2)) . c5)
by BVFUNC_1:def 7
.=
(((c2 '&' ('not' c3)) . c5) 'or' ((c3 '&' ('not' c4)) . c5)) 'or' ((c4 '&' ('not' c2)) . c5)
by BVFUNC_1:def 7
.=
(((c2 . c5) '&' (('not' c3) . c5)) 'or' ((c3 '&' ('not' c4)) . c5)) 'or' ((c4 '&' ('not' c2)) . c5)
by VALUAT_1:def 6
.=
(((c2 . c5) '&' (('not' c3) . c5)) 'or' ((c3 . c5) '&' (('not' c4) . c5))) 'or' ((c4 '&' ('not' c2)) . c5)
by VALUAT_1:def 6
.=
(((c2 . c5) '&' (('not' c3) . c5)) 'or' ((c3 . c5) '&' (('not' c4) . c5))) 'or' ((c4 . c5) '&' (('not' c2) . c5))
by VALUAT_1:def 6
.=
(((c2 . c5) '&' ('not' (c3 . c5))) 'or' ((c3 . c5) '&' (('not' c4) . c5))) 'or' ((c4 . c5) '&' (('not' c2) . c5))
by VALUAT_1:def 5
.=
(((c2 . c5) '&' ('not' (c3 . c5))) 'or' ((c3 . c5) '&' ('not' (c4 . c5)))) 'or' ((c4 . c5) '&' (('not' c2) . c5))
by VALUAT_1:def 5
.=
(((c2 . c5) '&' ('not' (c3 . c5))) 'or' ((c3 . c5) '&' ('not' (c4 . c5)))) 'or' ((c4 . c5) '&' ('not' (c2 . c5)))
by VALUAT_1:def 5
;
now
assume E4:
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c3))) 'or' (c2 '&' ('not' c4))) . c
5 <> TRUE
;
E5:
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c3))) 'or' (c2 '&' ('not' c4))) . c
5 =
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c3))) . c5) 'or' ((c2 '&' ('not' c4)) . c5)
by BVFUNC_1:def 7
.=
(((c3 '&' ('not' c2)) . c5) 'or' ((c4 '&' ('not' c3)) . c5)) 'or' ((c2 '&' ('not' c4)) . c5)
by BVFUNC_1:def 7
.=
(((c3 . c5) '&' (('not' c2) . c5)) 'or' ((c4 '&' ('not' c3)) . c5)) 'or' ((c2 '&' ('not' c4)) . c5)
by VALUAT_1:def 6
.=
(((c3 . c5) '&' (('not' c2) . c5)) 'or' ((c4 . c5) '&' (('not' c3) . c5))) 'or' ((c2 '&' ('not' c4)) . c5)
by VALUAT_1:def 6
.=
(((c3 . c5) '&' (('not' c2) . c5)) 'or' ((c4 . c5) '&' (('not' c3) . c5))) 'or' ((c2 . c5) '&' (('not' c4) . c5))
by VALUAT_1:def 6
;
E6:
(
((c3 . c5) '&' (('not' c2) . c5)) 'or' ((c4 . c5) '&' (('not' c3) . c5)) = TRUE or
((c3 . c5) '&' (('not' c2) . c5)) 'or' ((c4 . c5) '&' (('not' c3) . c5)) = FALSE )
by MARGREL1:39;
E7:
(
(c2 . c5) '&' (('not' c4) . c5) = TRUE or
(c2 . c5) '&' (('not' c4) . c5) = FALSE )
by MARGREL1:39;
E8:
(
(c3 . c5) '&' (('not' c2) . c5) = TRUE or
(c3 . c5) '&' (('not' c2) . c5) = FALSE )
by MARGREL1:39;
(
(c4 . c5) '&' (('not' c3) . c5) = TRUE or
(c4 . c5) '&' (('not' c3) . c5) = FALSE )
by MARGREL1:39;
then E9:
(
(c3 . c5) '&' (('not' c2) . c5) = FALSE &
(c4 . c5) '&' (('not' c3) . c5) = FALSE )
by E4, E5, E6, E8, BINARITH:19;
then E10:
( c
3 . c
5 = FALSE or
('not' c2) . c
5 = FALSE )
by MARGREL1:45;
E11:
( c
4 . c
5 = FALSE or
('not' c3) . c
5 = FALSE )
by E9, MARGREL1:45;
now
per cases
( c2 . c5 = FALSE or ('not' c4) . c5 = FALSE )
by E4, E5, E7, BINARITH:19, MARGREL1:45;
case E12:
c
2 . c
5 = FALSE
;
then
'not' (c2 . c5) = TRUE
by MARGREL1:41;
then E13:
'not' (c2 . c5) <> FALSE
by MARGREL1:43;
then
'not' (c3 . c5) = TRUE
by E10, MARGREL1:41, VALUAT_1:def 5;
then
'not' (c3 . c5) <> FALSE
by MARGREL1:43;
then
'not' (c4 . c5) = TRUE
by E11, MARGREL1:41, VALUAT_1:def 5;
then (((c2 . c5) '&' ('not' (c3 . c5))) 'or' ((c3 . c5) '&' ('not' (c4 . c5)))) 'or' ((c4 . c5) '&' ('not' (c2 . c5))) =
(FALSE 'or' (FALSE '&' TRUE )) 'or' (FALSE '&' TRUE )
by E10, E11, E12, E13, MARGREL1:49, VALUAT_1:def 5
.=
(FALSE 'or' FALSE ) 'or' (FALSE '&' TRUE )
by MARGREL1:49
.=
(FALSE 'or' FALSE ) 'or' FALSE
by MARGREL1:49
.=
FALSE 'or' FALSE
by BINARITH:7
.=
FALSE
by BINARITH:7
;
hence
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c3))) 'or' (c2 '&' ('not' c4))) . c
5 = TRUE
by E2, E3, MARGREL1:43;
end;
end;
end;
hence
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c3))) 'or' (c2 '&' ('not' c4))) . c
5 = TRUE
;
end;
hence
(((c3 '&' ('not' c2)) 'or' (c4 '&' ('not' c