You can cascade a set of context prefixes, separated by commas, onto one subject expression, effectively applying all the contexts (in order) to the subject expression, as in:
animate on, at time (t+1), with redraw off, coordsys local
(
...
)
All the context forms are true expressions, yielding the value of their subject expression, so:
pos0 = at time 35 $box01.position
pos1 = at time 75 $box01.position
assigns box01's position at time's 35 and 75 to variables 'pos0' and 'pos1'. The is particularly useful with the time context, since you can very easily do across-time computations. The operand to a time context can be any valid time value (integers are taken as frames for convenience), including subframe times down to the tick level. The animation system in MAX will interpolate animated parameters at these fine levels so you can do sub-frame simulation computations, for example, quite easily.