set m = [a_Type ,[{} ,0 ]];
set a = [an_Adj ,[{} ,0 ]];
( a_Type in {a_Type } & an_Adj in {an_Adj } & [(<*> Vars ),0 ] in [:QuasiLoci ,NAT :] )
by Th31, TARSKI:def 1, ZFMISC_1:def 2;
then
( [a_Type ,[{} ,0 ]] in Modes & [an_Adj ,[{} ,0 ]] in Attrs )
by ZFMISC_1:def 2;
then
( [a_Type ,[{} ,0 ]] in Modes \/ Attrs & [an_Adj ,[{} ,0 ]] in Modes \/ Attrs )
by XBOOLE_0:def 3;
then
( [a_Type ,[{} ,0 ]] in Constructors & [an_Adj ,[{} ,0 ]] in Constructors & the carrier' of MaxConstrSign = {* ,non_op } \/ Constructors )
by MAXdef, XBOOLE_0:def 3;
then reconsider m = [a_Type ,[{} ,0 ]], a = [an_Adj ,[{} ,0 ]] as OperSymbol of MaxConstrSign by XBOOLE_0:def 3;
A1:
( m is constructor & a is constructor )
by CNSTR2;
take
m
; :: according to ABCMIZ_1:def 12 :: thesis: ex a being OperSymbol of MaxConstrSign st
( the_result_sort_of m = a_Type & the_arity_of m = {} & the_result_sort_of a = an_Adj & the_arity_of a = {} )
take
a
; :: thesis: ( the_result_sort_of m = a_Type & the_arity_of m = {} & the_result_sort_of a = an_Adj & the_arity_of a = {} )
thus the_result_sort_of m =
m `1
by A1, MAXdef
.=
a_Type
by MCART_1:7
; :: thesis: ( the_arity_of m = {} & the_result_sort_of a = an_Adj & the_arity_of a = {} )
len (the_arity_of m) =
card ((m `2 ) `1 )
by A1, MAXdef
.=
card ([{} ,0 ] `1 )
by MCART_1:7
.=
0
by CARD_1:47, MCART_1:7
;
hence
the_arity_of m = {}
; :: thesis: ( the_result_sort_of a = an_Adj & the_arity_of a = {} )
thus the_result_sort_of a =
a `1
by A1, MAXdef
.=
an_Adj
by MCART_1:7
; :: thesis: the_arity_of a = {}
len (the_arity_of a) =
card ((a `2 ) `1 )
by A1, MAXdef
.=
card ([{} ,0 ] `1 )
by MCART_1:7
.=
0
by CARD_1:47, MCART_1:7
;
hence
the_arity_of a = {}
; :: thesis: verum