[css-easing-1] "chained together"

[jakearchibald]

From https://drafts.csswg.org/css-easing/#input-progress-value:

The input progress value is a real number in the range [-∞, ∞]. Typically, the input progress value is in the range [0, 1] but this may not be the case when easing functions are chained together.

The spec doesn't seem to describe what "chained together" means, or how/when this happens.

[jakearchibald]

Thanks! This clears it up