this is a weird math bug I've found, it produces this error message in lyx: Double superscript.
J^{l}^ {T}\end{array}\] I treat `x^1^2' essentially like `x^1{}^2' To explain you really have to look at the example file: http://www.md.kth.se/~chr/lyx/bugs/math1.lyx or see the screenshot: http://www.md.kth.se/~chr/lyx/bugs/math1.png Something seems to be happening when you open or save the document, basically it doesn't preserve math expressions properly. /Christian -- Christian Ridderström http://www.md.kth.se/~chr