terms N cons recip sqr N sqr 0 0 sqr s X s add sqr X dbl X dbl 0 0 dbl s X s s dbl X add 0 X X add s X Y s add X Y first 0 X nil first s X cons Y cons Y half 0 0 half s 0 0 half s s X s half X half dbl X X terms 1 cons 1 recip 1 sqr 1 0 0 s 1 add 2 dbl 1 first 2 nil 0 half 1 INNERMOST ./TRS/TRCSR/inn/ExSec11_1_Luc02a_L.trs