[here is my xls https://trtl.bz/2NLtTRX] The bond's present value (DCF) at any given point in time is called its "full price" (aka, cash, dirty). This full price is discontinuous because coupons pay discontinuously. If we subtract the accrued interest (AI) from the full price, we get the "flat price" (aka, quoted, clean). It is the flat price smoothly "pulls to par." Discuss this video here in our FRM forum: https://trtl.bz/2VqV9J2.