Regulations will provide that a single debt may qualify as partially acquisition and partially home equity indebtedness. Therefore, for example, if a taxpayer incurs a debt secured by his qualified residence and uses a portion of the debt proceeds to refinance an existing acquisition indebtedness and uses the remaining portion of the debt proceeds for purposes other than the substantial improvement of the residence, the portion of the debt used to refinance the acquisition indebtedness will qualify as acquisition indebtedness and the portion of the debt used for other purposes will generally be non-deductible home equity indebtedness.