How can I enter symbols from set theory in Isabelle/jEdit?

Question

How can I enter symbols like ∈, ⊆, ∪, and ∩ in Isabelle/jEdit? The Isabelle/HOL tutorial says, I should enter “:”, “<=”, “Un”, and “Int”. However, “<=” gives ≤, and the others are not translated to any symbols at all.

The only option I see so far is entering something like “\<in>” or a prefix thereof and selecting the desired symbol with the mouse. However, I want a keyboard-only input method.

Answer 1

You can type \in and then use tab to select the desired symbol, and also up/down arrow keys to select from the options.

Answer 2

I use the tab key when the desired symbol appears on the top of the list of the suggested symbols.

Also, for ⊆, I use "(=".