Dear Users,

1. The optics calculation now handles an optics with negative momentum (1 + DP) < 0 as optics for an antiparticle. For such a case
a) the betatron phase advances are negative, due to negative R12 or R34.
b) the signs of AX and AY are opposite to the usual case, for the same reason as a).
c) the bending by magnets and acceleration are reversed as expected.

Note that this is only valid for the optics calculation, and not for tracking yet at this moment.