In class I asked my professor whether mesh current loops could enclose resistors in a linear circuit (That is, extend over multiple mesh current loops). He said that this is allowable and the mesh current equations can be solved be appropriately picking the loops. However, a few different textbooks require that the current loops do not enclose any resistive elements. Is my professor corrrect? If not, can anyone offer an example where extending current loops over resistors does not work?