zOs/REXX/MAT

/* copy mat begin ****************************************************/
sqrt: procedure expose m.
parse arg n
    if n < 2 then
        return n
     k = 1
     g = n
     do while k+1 < g
         m = (g + k) % 2
         if m * m <= n then
             k = m
         else
             g = m
         end
     return k
endProcedure sqrt

isPrime: procedure expose m.
parse arg n
    if n < 2 then
        return 0
    if n // 2 = 0 then
        return n = 2
    do q=3 by 2 to sqrt(n)
        if n // q = 0 then
            return 0
        end
    return 1
endProcedure isPrime

nxPrime: procedure expose m.
parse arg n
    do i = n + (\ (n // 2)) by 2
        if isPrime(i) then
            return i
        end
endProcedure nxPrime

permut: procedure expose m.
parse arg m, p
    m.m.1 = 1
    do i=2 while p > 0
        j = i - (p // i)
        m.m.i = m.m.j
        m.m.j = i
        p = p % i
        end
    m.m.0 = i-1
    return i-1
endProcedure permut
/* copy mat end   ****************************************************/