Looking at the discard while in the middle of an action

[Squidwina]

Is a player allowed to look at his discard while he is in the middle of an action that involves choosing which of several cards to keep?

Examples:

Uxie Lv.X's Trade-Off power: The player draws the two cards, then looks at his discard, then decides which to keep and which to put at the bottom of his deck.

Pokedex: Same thing, except it's a trainer, not a power.


Thank you.

[PokePop]

It's all about being clear to your opponent about what you are doing.
If you communicate well and keep the piles of cards separate so they don't get mixed up (or look like you are trying to mix them on purpose), then there should be no problem.

If, on the other hand, you just start grabbing cards from various sources or hold cards from the deck and the discard in your hands at the same time, expect there to be objections and issues!