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53 lines
1.4 KiB
Plaintext
53 lines
1.4 KiB
Plaintext
NAME
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isprime - whether a small integer is prime
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SYNOPSIS
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isprime(x [,err])
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TYPES
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x int
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err int
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return int
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DESCRIPTION
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Determine if x is is a small prime. This function will return
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1 if x is a small prime. If x is even, this function will
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return 0. If x is negative or a small composite (non-prime),
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0 will be returned.
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If x is a large positive odd value and the err argument is
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given, this function return err. If x is a large positive odd
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value and the err argument is not given, an error will be
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generated.
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Note that normally this function returns the integer 0 or 1.
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If err is given and x is a large positive odd value, then err
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will be returned.
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EXAMPLE
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> print isprime(-3), isprime(1), isprime(2)
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0 0 1
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> print isprime(21701), isprime(1234577), isprime(1234579)
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1 1 0
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> print isprime(2^31-9), isprime(2^31-1), isprime(2^31+11)
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0 1 1
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> print isprime(2^32+1, -1), isprime(3^99, 2), isprime(4^99, 2)
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-1 2 0
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LIMITS
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err not given and (y is even or y < 2^32)
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LIBRARY
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FLAG zisprime(ZVALUE x) (return 1 if prime, 0 not prime, -1 if >= 2^32)
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SEE ALSO
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factor, lfactor, nextprime, prevprime, pfact, pix,
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isassoc, isatty, isblk, isconfig, isdefined, iserror, iseven, isfile,
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ishash, isident, isint, islist, ismat, ismult, isnull, isnum, isobj,
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isobjtype, isodd, isrand, israndom, isreal, isrel,
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issimple, issq, isstr, istype
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