A10: rng (1,1 .--> 1) c= {1} by FUNCOP_1:19;
{1} c= 2 by CARD_1:88, ZFMISC_1:12;
then A11: rng (1,1 .--> 1) c= 2 by A10, XBOOLE_1:1;
set f2 = (0 ,0 .--> 0 ) +* (0 ,1 .--> 0 );
set f1 = ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 );
set f = (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) +* (1,1 .--> 1);
A12: dom ((((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) +* (1,1 .--> 1)) = (dom (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 ))) \/ (dom (1,1 .--> 1)) by FUNCT_4:def 1
.= (dom (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 ))) \/ {[1,1]} by FUNCOP_1:19
.= ((dom ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 ))) \/ (dom (1,0 .--> 0 ))) \/ {[1,1]} by FUNCT_4:def 1
.= ((dom ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 ))) \/ {[1,0 ]}) \/ {[1,1]} by FUNCOP_1:19
.= (((dom (0 ,0 .--> 0 )) \/ (dom (0 ,1 .--> 0 ))) \/ {[1,0 ]}) \/ {[1,1]} by FUNCT_4:def 1
.= (((dom (0 ,0 .--> 0 )) \/ {[0 ,1]}) \/ {[1,0 ]}) \/ {[1,1]} by FUNCOP_1:19
.= (({[0 ,0 ]} \/ {[0 ,1]}) \/ {[1,0 ]}) \/ {[1,1]} by FUNCOP_1:19
.= ({[0 ,0 ],[0 ,1]} \/ {[1,0 ]}) \/ {[1,1]} by ENUMSET1:41
.= {[0 ,0 ],[0 ,1],[1,0 ]} \/ {[1,1]} by ENUMSET1:43
.= {[0 ,0 ],[0 ,1],[1,0 ],[1,1]} by ENUMSET1:46
.= [:2,2:] by CARD_1:88, ZFMISC_1:146 ;
A13: 1 c= 2 by CARD_1:87, CARD_1:88, ZFMISC_1:12;
rng (0 ,0 .--> 0 ) c= 1 by CARD_1:87, FUNCOP_1:19;
then A14: rng (0 ,0 .--> 0 ) c= 2 by A13, XBOOLE_1:1;
rng (0 ,1 .--> 0 ) c= 1 by CARD_1:87, FUNCOP_1:19;
then rng (0 ,1 .--> 0 ) c= 2 by A13, XBOOLE_1:1;
then A15: (rng (0 ,0 .--> 0 )) \/ (rng (0 ,1 .--> 0 )) c= 2 by A14, XBOOLE_1:8;
rng (1,0 .--> 0 ) c= 1 by CARD_1:87, FUNCOP_1:19;
then A16: rng (1,0 .--> 0 ) c= 2 by A13, XBOOLE_1:1;
rng ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) c= (rng (0 ,0 .--> 0 )) \/ (rng (0 ,1 .--> 0 )) by FUNCT_4:18;
then rng ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) c= 2 by A15, XBOOLE_1:1;
then A17: (rng ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 ))) \/ (rng (1,0 .--> 0 )) c= 2 by A16, XBOOLE_1:8;
rng (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) c= (rng ((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 ))) \/ (rng (1,0 .--> 0 )) by FUNCT_4:18;
then rng (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) c= 2 by A17, XBOOLE_1:1;
then A18: (rng (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 ))) \/ (rng (1,1 .--> 1)) c= 2 by A11, XBOOLE_1:8;
rng ((((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) +* (1,1 .--> 1)) c= (rng (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 ))) \/ (rng (1,1 .--> 1)) by FUNCT_4:18;
then rng ((((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) +* (1,1 .--> 1)) c= 2 by A18, XBOOLE_1:1;
hence (((0 ,0 .--> 0 ) +* (0 ,1 .--> 0 )) +* (1,0 .--> 0 )) +* (1,1 .--> 1) is BinOp of 2 by A12, FUNCT_2:def 1, RELSET_1:11; :: thesis: verum