LyX ⇒ Claims and proofs (etc.) within proofs

[CSMR]

A lot of the proofs I write involve claims and proofs of claims within proofs.

If I just create Claim and Proof environments in the proofs the output looks like
Proof:
Claim:
Proof:
QED
QED
Where QED represents the square symbol.

It is not very readable.

Creating a box with borders around the inner claim and proof preserves the structure but looks excessive.

Is there a way to create a box with a line on the left only? That would make structure more readable.

Or is there any other way to make environments within proofs have more of a visual structure?

Thanks!

[frabjous]

Perhaps by using the leftbar environment from the framed package?

[CSMR]

Thanks!
I'm not very familiar with LaTeX though.
To load the package, "\usepackage{framed}" in the preamble I suppose?
But in the list of environments (Standard, Section, Theorem, etc.) I can't see leftbar. Do I need to do something else to use it?

[frabjous]

Sorry, I didn't notice this was in the LyX subforum. I'm afraid I don't know how to make this work with LyX. Perhaps someone else will.