29 In regard to this controversy, counsel for the plaintiffs relied upon O 20 r 13(4)(a) which provides, amongst other things, that where a party alleges as fact that a person had knowledge or notice of some fact, matter or thing, then the court may, in such terms as it thinks just, order that party to serve on any other party the particulars of the facts on which he relies. The plaintiffs also relied upon Fox v H Wood (Harrow) Ltd [1963] 2 QB 601 at 604 in which it is said that an allegation that a person ought to have known something has implicit in it not only an allegation that he did not know something, which is a state of mind, but also an allegation that facts and circumstances exist from which he ought to have acquired, either by observation or inference, the knowledge of which he is deficient, and that some fault lies on him in failing to note, or draw an inference from, particular facts and circumstances. The court of appeal was of the view that in such a context particulars of the relevant facts and circumstances should be given. Particulars were normally ordered in such cases.