572.1. For the purposes of this section and paragraph b of section 572, the following rules apply:(a) the shares of the capital stock of a corporation that are at any time owned by, or that are deemed by this section to be at any time owned by, another corporation are deemed to be, at that time, owned by, or property of, each shareholder of the other corporation in the proportion that the fair market value at that time of the shares of the capital stock of the other corporation that, at that time, are owned by, or are property of, the shareholder is of the fair market value at that time of all the issued and outstanding shares of the capital stock of the other corporation;
(b) the shares of the capital stock of a corporation that are, or are deemed by this section to be, at any time, property of a partnership, are deemed to be, at that time, owned by, or property of, each member of the partnership in the proportion that the fair market value at that time of the member’s interest in the partnership is of the fair market value at that time of all interests in the partnership;
(c) the shares of the capital stock of a corporation that are at any time owned by, or that are deemed by this section to be at any time owned by, a non-discretionary trust (within the meaning of section 127.1) other than an exempt trust are deemed to be, at that time, owned by, or property of, each beneficiary of the trust in the proportion that the fair market value at that time of the beneficiary’s beneficial interest in the trust is of the fair market value at that time of all beneficial interests in the trust; and
(d) all of the shares of the capital stock of a corporation that are at any time owned by, or that are deemed by this section to be at any time owned by, a particular trust (other than a non-discretionary trust, within the meaning of section 127.1, or an exempt trust) are deemed to be, at that time, owned by, or property of,i. each beneficiary of the particular trust at that time, and
ii. each settlor (within the meaning of section 127.1) in respect of the particular trust at that time.