New in version 2.0.
True when expr is a sequence and expr is repetition free:
abjad> from abjad.tools import sequencetools
abjad> sequencetools.is_repetition_free_sequence([0, 1, 2, 6, 7, 8])
True
False when expr is a sequence and expr is not repetition free:
abjad> sequencetools.is_repetition_free_sequence([0, 1, 2, 2, 7, 8])
False
True when expr is an empty sequence:
abjad> sequencetools.is_repetition_free_sequence([])
True
False expr is not a sequence:
abjad> sequencetools.is_repetition_free_sequence(17)
False
Return boolean.