reserve i for Nat,
  j for Element of NAT,
  X,Y,x,y,z for set;
reserve C for initialized ConstructorSignature,
  s for SortSymbol of C,
  o for OperSymbol of C,
  c for constructor OperSymbol of C;
reserve a,b for expression of C, an_Adj C;

theorem Th43:
  (non_op C)term a is expression of C, an_Adj C &
  (non_op C)term a = [non_op, the carrier of C]-tree <*a*>
proof
A1: the_result_sort_of non_op C = an_Adj C by Def9;
A2: the_arity_of non_op C = <*an_Adj C*> by Def9;
  then
A3: len the_arity_of non_op C = 1 by FINSEQ_1:40;
A4: (the_arity_of non_op C).1 = an_Adj C by A2;
  then (non_op C)term a = [non_op, the carrier of C]-tree <*a*> by A3,Def30;
  hence thesis by A1,A3,A4,Th42;
end;
