(a) If a partnership for a definite term or particular undertaking is continued, without an express agreement, after the expiration of the term or completion of the undertaking, the rights and duties of the partners shall remain the same as they were at the expiration or completion, so far as is consistent with a partnership at will.
(b) If the partners, or those of them who habitually acted in the business during the term or undertaking, continue the business without any settlement or liquidation of the partnership, they shall be presumed to have agreed that the partnership will continue.