(1) If the claimant in probate proceedings disputes the interest of a defendant, the claimant must —
(a) deny the interest of that defendant; and
(b) state the claimant's reasons for so doing; in the statement of claim.
(2) In probate proceedings in which the interest by virtue of which a party claims to be entitled to a grant of letters of administration is disputed, the party disputing that interest must show in that party's statement of case that if the allegations made therein are proved he or she would be entitled to an interest in the estate.
(3) Any party who pleads that at the time when a will, the subject of the proceedings, was alleged to have been executed the testator did not know and approve of its contents, must specify the nature of the case on which he or she intends to rely, and no allegation in support of that plea which would be relevant in support of any of the following other pleas, that is to say that —
(a) at the time of the execution of the will the testator was not of sound mind, memory and understanding;
(b) the execution of the will was obtained by undue influence or fraud; or
(c) the will was not duly executed; may be made by that party unless that other plea is also set out in his or her statement of case.