:: SCHEMS_1 semantic presentation
scheme :: SCHEMS_1:sch 6
s6{ P
1[
set ], P
2[
set ] } :
ex b
1 being
set st
for b
2 being
set holds
( P
1[b
1] or P
2[b
2] )
provided
E1:
not ( ( for b
1 being
set holds
not P
1[b
1] ) & not for b
1 being
set holds P
2[b
1] )
scheme :: SCHEMS_1:sch 7
s7{ P
1[
set ], P
2[
set ] } :
not ( ( for b
1 being
set holds
not P
1[b
1] ) & not for b
1 being
set holds P
2[b
1] )
provided
E1:
ex b
1 being
set st
for b
2 being
set holds
( P
1[b
1] or P
2[b
2] )