def openTypeHheaCaretSlopeRunFallback(info):
    """
    Fallback to *openTypeHheaCaretSlopeRun*. If the italicAngle is zero,
    return 0. If italicAngle is non-zero, compute the slope run from the
    complementary openTypeHheaCaretSlopeRise.
    """
    italicAngle = getAttrWithFallback(info, "italicAngle")
    if italicAngle != 0:
        slopeRise = getAttrWithFallback(info, "openTypeHheaCaretSlopeRise")
        return otRound(math.tan(math.radians(-italicAngle)) * slopeRise)
    return 0
Fallback to *openTypeHheaCaretSlopeRun*. If the italicAngle is zero,
    return 0. If italicAngle is non-zero, compute the slope run from the
    complementary openTypeHheaCaretSlopeRise.