39gII and UTPT

[kakima]

UTPT(D,T) for T<0 seems to be returning UTPT(D,ABS(T)).

UTPT(20, 0) return 0.5, which is correct. For T=0 you expect half the values to be above that.

UTPT(20, 1.6) returns 0.0626, which agrees with every other calculator I've tried.

UTPT(20, -1.6) returns the same value, when it should be returning 1 - 0.0626 or 0.9374 which every other calculator I've tried including a 39g+ returns.