"2x^2 + 3y^2 <= 6" My guess is because lpsolve doesn't handle non linear programs. -- View this message in context: http://r.789695.n4.nabble.com/lpSolve-constraints-don-t-seem-to-have-an-effect-tp898253p3751751.html Sent from the R help mailing list archive at Nabble.com.