what does the (+x) mean if it is printed after enhancement.

example= Lunar Slash says E(4+); If this attack deals damage draw X cards...

thanks

You have to make a control check against a difficult of X. You are allowed to commit foundations to pass this control check. If you pass it you gain the effect

*STAMP*

doesn't matter if it's E/F/R, the notation (X+) in a cost always means to make a control check with a difficulty of X.