. _n
   .[] _a, 1000
   . _i
   . _j
   . _x
   . _sqrt_n
   . t0
   . p0
   . p1
   . t1
   . t2
   . t3
   . p2
   . p3
   . t4
   . p4
   . p5
   . t5
   . p6
   . p7
   . t6
   . p8
   . p9
   . t7
   . t8
   . p10
   . p11
   . t9
   . p12
   . p13
   . t10
: START
   .< _n
   = _x, _n
: L0
   / t0, _n, _x
   > p0, _x, t0
   == p1, p0, 0
   ?:= L1, p1
   / t1, _n, _x
   + t2, _x, t1
   / t3, t2, 2
   = _x, t3
   := L0
: L1
   = _sqrt_n, _x
   = _i, 2
: L2
   <= p2, _i, _n
   == p3, p2, 0
   ?:= L3, p3
   []= _a, _i, 0
   + t4, _i, 1
   = _i, t4
   := L2
: L3
   = _i, 2
: L4
   <= p4, _i, _sqrt_n
   == p5, p4, 0
   ?:= L5, p5
   =[] t5, _a, _i
   == p6, t5, 0
   == p7, p6, 0
   ?:= L6, p7
   + t6, _i, _i
   = _j, t6
: L7
   <= p8, _j, _n
   == p9, p8, 0
   ?:= L8, p9
   []= _a, _j, 1
   + t7, _j, _i
   = _j, t7
   := L7
: L8
   := L9
: L6
: L9
   + t8, _i, 1
   = _i, t8
   := L4
: L5
   = _i, 2
: L10
   <= p10, _i, _n
   == p11, p10, 0
   ?:= L11, p11
   =[] t9, _a, _i
   == p12, t9, 0
   == p13, p12, 0
   ?:= L12, p13
   .> _i
   := L13
: L12
: L13
   + t10, _i, 1
   = _i, t10
   := L10
: L11