reserve r,r1,r2, s,x for Real,
  i for Integer;

theorem Th62:
  rng arcsin = [.-PI/2,PI/2.]
proof
  dom (sin|[.-PI/2,PI/2.]) = [.-PI/2,PI/2.] by RELAT_1:62,SIN_COS:24;
  hence thesis by FUNCT_1:33;
end;
