Christopher Stowasser wrote:
I admit, that my last sentence is very confusing. Just forget about it. What I meant was: If I put the cursor before or behind the math box, i.e in the normal text, I can use the label function. As soon as I put the cursor in the math box the label function is inactive. Therefore I cannot label the equation in the math box. As long as I cannot asign a label to the equation it makes no sense to look at the pdf I guess.
Just to make sure we're all on the same page, you're talking about a displayed math inset (on its own line), right? If you have a math inset in the middle of a line of text, you won't be able to insert a label (the label item on the insert menu is grayed out), because inserting a label there makes no sense. A label in a math inset refers to the equation number, and in-line math insets don't get numbered.