Lydie (W) purchased the house eight months before the parties' marriage. The purchase price was $56,640.57. W made a down payment of $16,640.57 and secured a loan for the balance of the purchase price. She took title in her name alone as 'Lydie S. Doak, a single woman.' Prior to the marriage, she made seven monthly payments and reduced the principal loan balance by $245.18. H and W lived in the house until their separation in June 1977. Payments were from community funds, and they reduced the loan principal by $5,986.20. W remained in the house and continued to make payments, reducing the principal by an additional $581.07 up to the time of trial. The total principal paid on the purchase price was $23,453.02, the balance owing was $33,187.55, the market value of the house was $160,000, and the equity therein $126,812.45. The court held that it was W's separate property with a community interest acquired during the marriage. The community interest was to be determined according to the ratio that the reduction of principal resulting from community funds bears to the reduction of principal from separate funds. No credit was given for the amount paid for interest, taxes, and insurance. The community interest was calculated by multiplying the equity value of the house by the ratio of the community's reduction of principal to the total amount of principal reduction by both community and separate property ($5,986.20 divided by $ 23,453.02 equals 25.5242 percent). The amount of the community interest was thus determined to be $32,367.86. W's separate property interest was calculated by multiplying the equity value of the house by the ratio of the separate property reduction of principal to the total amount of principal reduction ($17,466.82 divided by $23,453.02 equals 74.4758 percent). W's separate property interest was thus determined to be $94,444.59. H and W disagree as to how the interest is to be determined. H contends that the community property interest should be based upon the full amount of the payments made, which includes interest, taxes, and insurance, rather than only on the amount by which the payments reduce the principal.