let G be non empty RelStr ; :: thesis: for H1, H2 being RelStr st the carrier of H1 misses the carrier of H2 & ( RelStr(# the carrier of G,the InternalRel of G #) = union_of H1,H2 or RelStr(# the carrier of G,the InternalRel of G #) = sum_of H1,H2 ) holds
( H1 is full SubRelStr of G & H2 is full SubRelStr of G )

let H1, H2 be RelStr ; :: thesis: ( the carrier of H1 misses the carrier of H2 & ( RelStr(# the carrier of G,the InternalRel of G #) = union_of H1,H2 or RelStr(# the carrier of G,the InternalRel of G #) = sum_of H1,H2 ) implies ( H1 is full SubRelStr of G & H2 is full SubRelStr of G ) )
assume that
A1: the carrier of H1 misses the carrier of H2 and
A2: ( RelStr(# the carrier of G,the InternalRel of G #) = union_of H1,H2 or RelStr(# the carrier of G,the InternalRel of G #) = sum_of H1,H2 ) ; :: thesis: ( H1 is full SubRelStr of G & H2 is full SubRelStr of G )
set cH1 = the carrier of H1;
set cH2 = the carrier of H2;
set IH1 = the InternalRel of H1;
set IH2 = the InternalRel of H2;
set H1H2 = [:the carrier of H1,the carrier of H2:];
set H2H1 = [:the carrier of H2,the carrier of H1:];
per cases ( RelStr(# the carrier of G,the InternalRel of G #) = union_of H1,H2 or RelStr(# the carrier of G,the InternalRel of G #) = sum_of H1,H2 ) by A2;
suppose A3: RelStr(# the carrier of G,the InternalRel of G #) = union_of H1,H2 ; :: thesis: ( H1 is full SubRelStr of G & H2 is full SubRelStr of G )
then A4: the InternalRel of G = the InternalRel of H1 \/ the InternalRel of H2 by NECKLA_2:def 2;
then A5: the InternalRel of H1 c= the InternalRel of G by XBOOLE_1:7;
A6: the carrier of G = the carrier of H1 \/ the carrier of H2 by A3, NECKLA_2:def 2;
then A7: the carrier of H1 c= the carrier of G by XBOOLE_1:7;
A8: the carrier of H2 c= the carrier of G by A6, XBOOLE_1:7;
A9: the InternalRel of H2 c= the InternalRel of G by A4, XBOOLE_1:7;
A10: the InternalRel of H1 = the InternalRel of G |_2 the carrier of H1
proof
thus the InternalRel of H1 c= the InternalRel of G |_2 the carrier of H1 :: according to XBOOLE_0:def 10 :: thesis: the InternalRel of G |_2 the carrier of H1 c= the InternalRel of H1
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of H1 or a in the InternalRel of G |_2 the carrier of H1 )
assume A11: a in the InternalRel of H1 ; :: thesis: a in the InternalRel of G |_2 the carrier of H1
the InternalRel of G = the InternalRel of H1 \/ the InternalRel of H2 by A3, NECKLA_2:def 2;
then the InternalRel of H1 c= the InternalRel of G by XBOOLE_1:7;
hence a in the InternalRel of G |_2 the carrier of H1 by A11, XBOOLE_0:def 4; :: thesis: verum
end;
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of G |_2 the carrier of H1 or a in the InternalRel of H1 )
assume a in the InternalRel of G |_2 the carrier of H1 ; :: thesis: a in the InternalRel of H1
then A12: ( a in the InternalRel of G & a in [:the carrier of H1,the carrier of H1:] ) by XBOOLE_0:def 4;
then A13: a in the InternalRel of H1 \/ the InternalRel of H2 by A3, NECKLA_2:def 2;
per cases ( a in the InternalRel of H1 or a in the InternalRel of H2 ) by A13, XBOOLE_0:def 3;
suppose a in the InternalRel of H1 ; :: thesis: a in the InternalRel of H1
hence a in the InternalRel of H1 ; :: thesis: verum
end;
suppose a in the InternalRel of H2 ; :: thesis: a in the InternalRel of H1
then consider x, y being set such that
A14: ( a = [x,y] & x in the carrier of H2 & y in the carrier of H2 ) by RELSET_1:6;
consider x1, y1 being set such that
A15: ( x1 in the carrier of H1 & y1 in the carrier of H1 & a = [x1,y1] ) by A12, ZFMISC_1:def 2;
( x in the carrier of H1 & x in the carrier of H2 ) by A14, A15, ZFMISC_1:33;
hence a in the InternalRel of H1 by A1, XBOOLE_0:3; :: thesis: verum
end;
end;
end;
the InternalRel of H2 = the InternalRel of G |_2 the carrier of H2
proof
thus the InternalRel of H2 c= the InternalRel of G |_2 the carrier of H2 :: according to XBOOLE_0:def 10 :: thesis: the InternalRel of G |_2 the carrier of H2 c= the InternalRel of H2
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of H2 or a in the InternalRel of G |_2 the carrier of H2 )
assume A16: a in the InternalRel of H2 ; :: thesis: a in the InternalRel of G |_2 the carrier of H2
the InternalRel of G = the InternalRel of H1 \/ the InternalRel of H2 by A3, NECKLA_2:def 2;
then the InternalRel of H2 c= the InternalRel of G by XBOOLE_1:7;
hence a in the InternalRel of G |_2 the carrier of H2 by A16, XBOOLE_0:def 4; :: thesis: verum
end;
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of G |_2 the carrier of H2 or a in the InternalRel of H2 )
assume a in the InternalRel of G |_2 the carrier of H2 ; :: thesis: a in the InternalRel of H2
then A17: ( a in the InternalRel of G & a in [:the carrier of H2,the carrier of H2:] ) by XBOOLE_0:def 4;
then A18: a in the InternalRel of H1 \/ the InternalRel of H2 by A3, NECKLA_2:def 2;
per cases ( a in the InternalRel of H1 or a in the InternalRel of H2 ) by A18, XBOOLE_0:def 3;
suppose a in the InternalRel of H1 ; :: thesis: a in the InternalRel of H2
then consider x, y being set such that
A19: ( a = [x,y] & x in the carrier of H1 & y in the carrier of H1 ) by RELSET_1:6;
consider x1, y1 being set such that
A20: ( x1 in the carrier of H2 & y1 in the carrier of H2 & a = [x1,y1] ) by A17, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A19, A20, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A19, A20, XBOOLE_0:def 4;
hence a in the InternalRel of H2 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
suppose a in the InternalRel of H2 ; :: thesis: a in the InternalRel of H2
hence a in the InternalRel of H2 ; :: thesis: verum
end;
end;
end;
hence ( H1 is full SubRelStr of G & H2 is full SubRelStr of G ) by A5, A7, A8, A9, A10, YELLOW_0:def 13, YELLOW_0:def 14; :: thesis: verum
end;
suppose A21: RelStr(# the carrier of G,the InternalRel of G #) = sum_of H1,H2 ; :: thesis: ( H1 is full SubRelStr of G & H2 is full SubRelStr of G )
then A22: the InternalRel of G = ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by NECKLA_2:def 3;
then A23: (the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:] c= the InternalRel of G by XBOOLE_1:7;
the InternalRel of H1 c= the InternalRel of H1 \/ (the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) by XBOOLE_1:7;
then the InternalRel of H1 c= (the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:] by XBOOLE_1:4;
then A24: the InternalRel of H1 c= the InternalRel of G by A23, XBOOLE_1:1;
A25: the carrier of G = the carrier of H1 \/ the carrier of H2 by A21, NECKLA_2:def 3;
then A26: the carrier of H1 c= the carrier of G by XBOOLE_1:7;
A27: the carrier of H2 c= the carrier of G by A25, XBOOLE_1:7;
the InternalRel of H2 c= the InternalRel of H1 \/ (the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) by XBOOLE_1:7, XBOOLE_1:10;
then the InternalRel of H2 c= (the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:] by XBOOLE_1:4;
then A28: the InternalRel of H2 c= ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by XBOOLE_1:10;
A29: the InternalRel of H1 = the InternalRel of G |_2 the carrier of H1
proof
thus the InternalRel of H1 c= the InternalRel of G |_2 the carrier of H1 :: according to XBOOLE_0:def 10 :: thesis: the InternalRel of G |_2 the carrier of H1 c= the InternalRel of H1
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of H1 or a in the InternalRel of G |_2 the carrier of H1 )
assume A30: a in the InternalRel of H1 ; :: thesis: a in the InternalRel of G |_2 the carrier of H1
the InternalRel of G = ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by A21, NECKLA_2:def 3
.= the InternalRel of H1 \/ ((the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:]) by XBOOLE_1:113 ;
then the InternalRel of H1 c= the InternalRel of G by XBOOLE_1:7;
hence a in the InternalRel of G |_2 the carrier of H1 by A30, XBOOLE_0:def 4; :: thesis: verum
end;
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of G |_2 the carrier of H1 or a in the InternalRel of H1 )
assume a in the InternalRel of G |_2 the carrier of H1 ; :: thesis: a in the InternalRel of H1
then A31: ( a in the InternalRel of G & a in [:the carrier of H1,the carrier of H1:] ) by XBOOLE_0:def 4;
then a in ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by A21, NECKLA_2:def 3;
then a in the InternalRel of H1 \/ ((the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:]) by XBOOLE_1:113;
then ( a in the InternalRel of H1 or a in (the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] ) by XBOOLE_0:def 3;
then ( a in the InternalRel of H1 or a in the InternalRel of H2 \/ ([:the carrier of H1,the carrier of H2:] \/ [:the carrier of H2,the carrier of H1:]) ) by XBOOLE_1:4;
then A32: ( a in the InternalRel of H1 or a in the InternalRel of H2 or a in [:the carrier of H1,the carrier of H2:] \/ [:the carrier of H2,the carrier of H1:] ) by XBOOLE_0:def 3;
per cases ( a in the InternalRel of H1 or a in the InternalRel of H2 or a in [:the carrier of H1,the carrier of H2:] or a in [:the carrier of H2,the carrier of H1:] ) by A32, XBOOLE_0:def 3;
suppose a in the InternalRel of H1 ; :: thesis: a in the InternalRel of H1
hence a in the InternalRel of H1 ; :: thesis: verum
end;
suppose a in the InternalRel of H2 ; :: thesis: a in the InternalRel of H1
then consider x, y being set such that
A33: ( a = [x,y] & x in the carrier of H2 & y in the carrier of H2 ) by RELSET_1:6;
consider x1, y1 being set such that
A34: ( x1 in the carrier of H1 & y1 in the carrier of H1 & a = [x1,y1] ) by A31, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A33, A34, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A33, A34, XBOOLE_0:def 4;
hence a in the InternalRel of H1 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
suppose a in [:the carrier of H1,the carrier of H2:] ; :: thesis: a in the InternalRel of H1
then consider x, y being set such that
A35: ( x in the carrier of H1 & y in the carrier of H2 & a = [x,y] ) by ZFMISC_1:def 2;
consider x1, y1 being set such that
A36: ( x1 in the carrier of H1 & y1 in the carrier of H1 & a = [x1,y1] ) by A31, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A35, A36, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A35, A36, XBOOLE_0:def 4;
hence a in the InternalRel of H1 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
suppose a in [:the carrier of H2,the carrier of H1:] ; :: thesis: a in the InternalRel of H1
then consider x, y being set such that
A37: ( x in the carrier of H2 & y in the carrier of H1 & a = [x,y] ) by ZFMISC_1:def 2;
consider x1, y1 being set such that
A38: ( x1 in the carrier of H1 & y1 in the carrier of H1 & a = [x1,y1] ) by A31, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A37, A38, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A37, A38, XBOOLE_0:def 4;
hence a in the InternalRel of H1 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
end;
end;
the InternalRel of H2 = the InternalRel of G |_2 the carrier of H2
proof
thus the InternalRel of H2 c= the InternalRel of G |_2 the carrier of H2 :: according to XBOOLE_0:def 10 :: thesis: the InternalRel of G |_2 the carrier of H2 c= the InternalRel of H2
proof
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of H2 or a in the InternalRel of G |_2 the carrier of H2 )
assume A39: a in the InternalRel of H2 ; :: thesis: a in the InternalRel of G |_2 the carrier of H2
the InternalRel of G = ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by A21, NECKLA_2:def 3;
then the InternalRel of G = the InternalRel of H2 \/ ((the InternalRel of H1 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:]) by XBOOLE_1:113;
then the InternalRel of H2 c= the InternalRel of G by XBOOLE_1:7;
hence a in the InternalRel of G |_2 the carrier of H2 by A39, XBOOLE_0:def 4; :: thesis: verum
end;
let a be set ; :: according to TARSKI:def 3 :: thesis: ( not a in the InternalRel of G |_2 the carrier of H2 or a in the InternalRel of H2 )
assume a in the InternalRel of G |_2 the carrier of H2 ; :: thesis: a in the InternalRel of H2
then A40: ( a in the InternalRel of G & a in [:the carrier of H2,the carrier of H2:] ) by XBOOLE_0:def 4;
then a in ((the InternalRel of H1 \/ the InternalRel of H2) \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] by A21, NECKLA_2:def 3;
then a in the InternalRel of H1 \/ ((the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:]) by XBOOLE_1:113;
then ( a in the InternalRel of H1 or a in (the InternalRel of H2 \/ [:the carrier of H1,the carrier of H2:]) \/ [:the carrier of H2,the carrier of H1:] ) by XBOOLE_0:def 3;
then ( a in the InternalRel of H1 or a in the InternalRel of H2 \/ ([:the carrier of H1,the carrier of H2:] \/ [:the carrier of H2,the carrier of H1:]) ) by XBOOLE_1:4;
then A41: ( a in the InternalRel of H1 or a in the InternalRel of H2 or a in [:the carrier of H1,the carrier of H2:] \/ [:the carrier of H2,the carrier of H1:] ) by XBOOLE_0:def 3;
per cases ( a in the InternalRel of H1 or a in the InternalRel of H2 or a in [:the carrier of H1,the carrier of H2:] or a in [:the carrier of H2,the carrier of H1:] ) by A41, XBOOLE_0:def 3;
suppose a in the InternalRel of H1 ; :: thesis: a in the InternalRel of H2
then consider x, y being set such that
A42: ( a = [x,y] & x in the carrier of H1 & y in the carrier of H1 ) by RELSET_1:6;
consider x1, y1 being set such that
A43: ( x1 in the carrier of H2 & y1 in the carrier of H2 & a = [x1,y1] ) by A40, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A42, A43, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A42, A43, XBOOLE_0:def 4;
hence a in the InternalRel of H2 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
suppose a in the InternalRel of H2 ; :: thesis: a in the InternalRel of H2
hence a in the InternalRel of H2 ; :: thesis: verum
end;
suppose a in [:the carrier of H1,the carrier of H2:] ; :: thesis: a in the InternalRel of H2
then consider x, y being set such that
A44: ( x in the carrier of H1 & y in the carrier of H2 & a = [x,y] ) by ZFMISC_1:def 2;
consider x1, y1 being set such that
A45: ( x1 in the carrier of H2 & y1 in the carrier of H2 & a = [x1,y1] ) by A40, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A44, A45, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A44, A45, XBOOLE_0:def 4;
hence a in the InternalRel of H2 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
suppose a in [:the carrier of H2,the carrier of H1:] ; :: thesis: a in the InternalRel of H2
then consider x, y being set such that
A46: ( x in the carrier of H2 & y in the carrier of H1 & a = [x,y] ) by ZFMISC_1:def 2;
consider x1, y1 being set such that
A47: ( x1 in the carrier of H2 & y1 in the carrier of H2 & a = [x1,y1] ) by A40, ZFMISC_1:def 2;
( x = x1 & y = y1 ) by A46, A47, ZFMISC_1:33;
then the carrier of H1 /\ the carrier of H2 <> {} by A46, A47, XBOOLE_0:def 4;
hence a in the InternalRel of H2 by A1, XBOOLE_0:def 7; :: thesis: verum
end;
end;
end;
hence ( H1 is full SubRelStr of G & H2 is full SubRelStr of G ) by A22, A24, A26, A27, A28, A29, YELLOW_0:def 13, YELLOW_0:def 14; :: thesis: verum
end;
end;