J Austral Math Soc Ser B 37 pp549--570, 1996.
(Received 19 August 1993; revised 21 August 1994)
In this paper we propose a P1 finite element preconditioning using the so-called 'hat-function', to a collocation scheme constructed by quadratic splines for a 2nd-order separable elliptic operator and we show that the resulting preconditioning system of equations is well conditioned with the condition number independent of the number of unknowns.