set C = MaxConstrSign ;
set m = [a_Type ,[{} ,0 ]];
set a = [an_Adj ,[{} ,0 ]];
set f = [a_Term ,[{} ,0 ]];
A1: a_Type in {a_Type } by TARSKI:def 1;
A2: an_Adj in {an_Adj } by TARSKI:def 1;
A3: a_Term in {a_Term } by TARSKI:def 1;
A4: [(<*> Vars ),0 ] in [:QuasiLoci ,NAT :] by Th29, ZFMISC_1:def 2;
then A5: [a_Type ,[{} ,0 ]] in Modes by A1, ZFMISC_1:def 2;
A6: [an_Adj ,[{} ,0 ]] in Attrs by A2, A4, ZFMISC_1:def 2;
A7: [a_Term ,[{} ,0 ]] in Funcs by A3, A4, ZFMISC_1:def 2;
A8: [a_Type ,[{} ,0 ]] in Modes \/ Attrs by A5, XBOOLE_0:def 3;
A9: [an_Adj ,[{} ,0 ]] in Modes \/ Attrs by A6, XBOOLE_0:def 3;
A10: [a_Type ,[{} ,0 ]] in Constructors by A8, XBOOLE_0:def 3;
A11: [an_Adj ,[{} ,0 ]] in Constructors by A9, XBOOLE_0:def 3;
A12: [a_Term ,[{} ,0 ]] in Constructors by A7, XBOOLE_0:def 3;
the carrier' of MaxConstrSign = {* ,non_op } \/ Constructors by Def24;
then reconsider m = [a_Type ,[{} ,0 ]], a = [an_Adj ,[{} ,0 ]], f = [a_Term ,[{} ,0 ]] as OperSymbol of MaxConstrSign by A10, A11, A12, XBOOLE_0:def 3;
A13: m is constructor by Def11;
A14: a is constructor by Def11;
A15: f is constructor by Def11;
A16: the ResultSort of MaxConstrSign . m = m `1 by A13, Def24;
A17: the ResultSort of MaxConstrSign . a = a `1 by A14, Def24;
A18: the ResultSort of MaxConstrSign . f = f `1 by A15, Def24;
A19: the ResultSort of MaxConstrSign . m = a_Type by A16, MCART_1:7;
A20: the ResultSort of MaxConstrSign . a = an_Adj by A17, MCART_1:7;
A21: the ResultSort of MaxConstrSign . f = a_Term by A18, MCART_1:7;
A22: the carrier of MaxConstrSign = {a_Type ,an_Adj ,a_Term } by Def9;
let x be set ; :: according to TARSKI:def 3,ABCMIZ_1:def 54 :: thesis: ( not x in the carrier of MaxConstrSign or x in rng the ResultSort of MaxConstrSign )
assume x in the carrier of MaxConstrSign ; :: thesis: x in rng the ResultSort of MaxConstrSign
then ( x = a_Type or x = an_Adj or x = a_Term ) by A22, ENUMSET1:def 1;
hence x in rng the ResultSort of MaxConstrSign by A19, A20, A21, FUNCT_2:6; :: thesis: verum