aa ( b ( c ( d ( ))))start,end,start,end,startstartendend))))a ( b ( c ( d ( start,end,start,end,startstartendendSTARTENDbcdSTARTEND0%100%0%0%100%100%0%100%a0% - t100% + tbcd0% - t100% + tstart =end = 0%100%start =end = 0% - t100% + tFROM PARENT ELEMENTFROM CHILD ELEMENT