Cumulative sums of sequence:
abjad> from abjad.tools import mathtools
abjad> mathtools.cumulative_sums([1, 2, 3, 4, 5, 6, 7, 8])
[1, 3, 6, 10, 15, 21, 28, 36]
Raise type error when sequence is neither list nor tuple.
Raise value error on empty sequence.
Return list.
Changed in version 2.0: renamed sequencetools.cumulative_sums() to mathtools.cumulative_sums().