local fmt = require "fmt"

local multiplier = |n1, n2| -> (|m| -> n1 * n2 * m)

local function ordered_collection()
    local x  = 2.0
    local xi = 0.5
    local y  = 4.0
    local yi = 0.25
    local z  = x + y
    local zi = 1.0 / ( x + y )
    return {x, y, z}, {xi, yi, zi}
end

local oc1, oc2 = ordered_collection()
for i = 1, 3 do
    local x = oc1[i]
    local y = oc2[i]
    local m = 0.5  -- rather than 1 to compare with first-class functions task
    fmt.print("%0.1g * %f * %0.1g = %0.1g", x, y, m, multiplier(x, y)(m))
end