let a, b, e, d be complex number ; :: thesis: ((a - b) + e) / d = ((a / d) - (b / d)) + (e / d)
thus ((a - b) + e) / d = ((a - b) / d) + (e / d) by Th63
.= ((a / d) - (b / d)) + (e / d) by Th121 ; :: thesis: verum