Section 86 is primarily concerned with the quantification or satisfaction (by set-off) of provable debts. The section is, as has been seen, in a Division concerned with "Proof of Debts". It operates in a context where there is a debt of "a person who has become a bankrupt" which would, apart from set-off, be provable in the bankruptcy (see above). As a matter of language, the words of s. 86(1)(a) and (b) allow a set-off, against such a debt, of the amount due in respect of a mutual credit, a mutual debt or other mutual dealings regardless of whether the claim in respect of that amount vested in the trustee in bankruptcy. On the other hand, general considerations of true mutuality and the context provided by s. 86(1)(c), with its assumption that any surplus or "balance" will be either provable in the bankruptcy or recoverable by the trustee, support the view that, upon the preferable construction of s. 86, set-off between claims by and claims against a person who has become bankrupt is allowed only if the bankrupt estate is entitled to the benefit as well as being subjected to the burden of the respective claims. That construction is also supported by general considerations of bankruptcy law since, if the trustee is entitled to the benefit of a set-off of claims which do not vest in him, the result could be that set-off under s. 86 would defeat the policy of the Act that bankruptcy should not denude the bankrupt of certain beneficial rights. On the other hand, s. 86 speaks as at the time of the making of the sequestration order and operates by reference to the dealings and entitlement of "a person who has become a bankrupt" as distinct from the entitlement of the trustee in bankruptcy which is only ascertained, when the section is applicable, after the account required by s. 86(1)(a) has been taken and after a set-off under s. 86(1)(b) has taken effect. On balance, it appears to us that s. 86 should be construed as allowing a set-off in favour of the trustee in bankruptcy only in respect of a claim which vests in him under the bankruptcy. It is, however, strictly unnecessary to express a concluded view on this aspect of the matter since, as has been seen, the claims for fraudulent misrepresentation against Mrs. McIntyre would, if a sequestration order had been made at the time of the relevant special resolution, have vested in the trustee in bankruptcy. That being so, the real question raised by this submission is, upon analysis, a somewhat different one to that which was directly addressed in argument. It is whether, in the case of a composition under Pt X, there can be no set-off between a claim provable in the composition and a claim by the debtor which is not assigned to the trustee under the composition notwithstanding that there would have been a set-off in bankruptcy between those claims as claims in respect of mutual dealings if, in the words of s. 243, "a sequestration order had been made against the debtor on the day on which the special resolution was passed". As a matter of the ordinary meaning of the words of s. 243, the answer to that question is in the negative, that is to say, to the effect that a set-off is not precluded in those circumstances. A negative answer to the question is also supported by considerations of "substantial justice" and policy.