tomo-Int.prev_prime.3

(38 lines)
   1 '\" t
   2 .\" Copyright (c) 2026 Bruce Hill
   3 .\" All rights reserved.
   4 .\"
   5 .TH Int.prev_prime 3 2026-01-19 "Tomo man-pages"
   6 .SH NAME
   7 Int.prev_prime \- get the previous prime
   8 .SH LIBRARY
   9 Tomo Standard Library
  10 .SH SYNOPSIS
  11 .nf
  12 .BI Int.prev_prime\ :\ func(x:\ Int\ ->\ Int?)
  13 .fi
  14 .SH DESCRIPTION
  15 Finds the previous prime number less than the given integer. If there is no previous prime number (i.e. if a number less than `2` is provided), then the function will create a runtime error.
  16 
  17 
  18 .SH ARGUMENTS
  19 
  20 .TS
  21 allbox;
  22 lb lb lbx
  23 l l l.
  24 Name	Type	Description
  25 x	Int	The integer before which to find the previous prime. 
  26 .TE
  27 .SH RETURN
  28 The previous prime number less than `x`, or `none` if `x` is less than 2.
  29 
  30 .SH NOTES
  31 This function is _probabilistic_, but the chances of getting an incorrect answer are astronomically small (on the order of 10^(-30)). See [the GNU MP docs](https://gmplib.org/manual/Number-Theoretic-Functions#index-mpz_005fprobab_005fprime_005fp) for more details.
  32 
  33 .SH EXAMPLES
  34 .EX
  35 assert 11.prev_prime() == 7
  36 .EE
  37 .SH SEE ALSO
  38 .BR Tomo-Int (3)