$LimitTo4IRUnsafe is a global variable that determines
whether the simplifications described in $LimitTo4 are
applied also to C and D Passarino-Veltman functions. In this case
it is assumed that such functions are either IR finite, or the IR
divergences are regulated without using dimensional regularization
(i.e. by introducing fictitious masses). Otherwise the results will be
inconsistent. If this option is activated, it is the task of the user to
ensure that IR divergences are properly regulated, such that no mixing
of \varepsilon from IR and UV can
occur. The default value is False.
Overview, PaVe, PaVeReduce, OneLoop, $LimitTo4, PaVeLimitTo4.
$LimitTo4IRUnsafe\text{False}