plus
Runs both animations on every frame and merges what they answer.
Opacities and scales multiply, offsets add, so a fade combined with a slide carries both. The result compares by value exactly as far as its two operands do: two built-in helpers combine into something structurally equal, and anything touching a caller's lambda compares by identity.
Return
An animation carrying both.
Parameters
other
The animation to run alongside this one.