670.86. For the purposes of section 670.85, the rebate to which a builder is entitled, in respect of the residential complex or of the addition to it, is equal to the amount determined by the formula
A × 7.5% × (1 − B/C).
For the purposes of the formula,(1) A is the amount of the rebate to which the builder is entitled under subsection 1 of section 256.77 of the Excise Tax Act (Revised Statutes of Canada, 1985, chapter E-15) in respect of the residential complex or of the addition;
(2) B is the amount by which the amount of the rebate to which the builder is entitled under section 378.8 or 378.14 in respect of the residential complex or of the addition, exceeds the result obtained by multiplying 7.5% by the amount of the rebate to which the builder is entitled under subsection 4 of section 256.2 of the Excise Tax Act in respect of the residential complex or of the addition; and
(3) C is the amount by which the amount of the tax payable under section 16 in respect of the supply deemed to have been made under section 225 or 226, exceeds the result obtained by multiplying 7.5% by the amount of the rebate to which the builder is entitled under subsection 4 of section 256.2 of the Excise Tax Act in respect of the residential complex or of the addition.