Hi, I'm getting a "matrix not positive definite" error for the following (wrong) command: open denmark var 3 LRM LRM LRY The message is of course correct, but I'm wondering whether duplication of terms should be caught by gretl -- note that gretl does that already for the 'ols' command (e.g. try "ols LRM const LRY LRY"). Any other estimation commands that could be affected? thanks, sven