[Jprogramming] multiplication bug

[Andrew Nikitin]

i am trying to multiply several integers modulo small prime number here and fail at that.

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   NB. highest power of prime x that divides !y

   pffact=:([: +/ ] <.@% [ ^ 1 + [: i. <.@^.)

   P=:9+1e9

   pw=.1e9 pffact">~ pr=.p:i.240 NB. first few primes and their powers

   1 p: P NB. P is prime

1
   datatype P
integer

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here is a list of integers I am trying to multiply
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   mul=.1+pr (P&|@^) 2 (P&|@*) pw
   datatype mul
integer

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And here is what happens when I actually multiply them:
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      P&|@*/ mul
0

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which is not the right answer
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      P&|@*/ |.mul
3.90562e7

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