FORALL x LET COS (x)^2 = 1 - SIN (x)^2;
FORALL x LET EXP(LOG(x)) = x;
FORALL x LET (EXP(-LOG(x))) = 1/x;
FORALL x LET E^(LOG(x)) = x;
FORALL x LET (E^(-LOG(x))) = 1/x;
END;
