def __init__(self, tpmats):
        bc_mats = extract_bc_matrices([tpmats])
        self.tpmats = tpmats
        self.bc_mats = bc_mats
        self._lu = None
        m = tpmats[0]
        self.T = T = m.space
        assert m._issimplified is False, "Cannot use simplified matrices with this solver"
        mat = m.diags(format='csc')
        for m in tpmats[1:]:
            mat = mat + m.diags('csc')
        self.mat = mat