set X = { x where x is Element of Funcs {0 ,one },REAL : x . one = 0 } ;
thus
REAL c= COMPLEX
by XBOOLE_1:7; XBOOLE_0:def 8 not REAL = COMPLEX
REAL+ c= REAL+ \/ [:{{} },REAL+ :]
by XBOOLE_1:7;
then A2:
REAL+ c= REAL
by ARYTM_2:3, ZFMISC_1:40;
then reconsider z = 0 , j = 1 as Element of REAL by ARYTM_2:21;
A3:
not 0 ,1 --> z,j in REAL
by Lm7;
( rng (0 ,1 --> 0 ,1) c= {0 ,1} & {0 ,1} c= REAL )
by A2, ARYTM_2:21, FUNCT_4:65, ZFMISC_1:38;
then
( dom (0 ,1 --> 0 ,1) = {0 ,1} & rng (0 ,1 --> 0 ,1) c= REAL )
by FUNCT_4:65, XBOOLE_1:1;
then
0 ,1 --> 0 ,1 in Funcs {0 ,one },REAL
by FUNCT_2:def 2;
then
0 ,1 --> 0 ,1 in (Funcs {0 ,one },REAL ) \ { x where x is Element of Funcs {0 ,one },REAL : x . one = 0 }
by A1, XBOOLE_0:def 5;
hence
not REAL = COMPLEX
by A3, XBOOLE_0:def 3; verum