On 24 Aug 2023, at 06:03, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:

[…]

I would drop the column check in this case.

    for i = 0,9 do
        context.startxrow()
            context.startxcell()
                context(i)
            context.stopxcell()
            context.startxcell()
                context(math.mod(i*i,10))
            context.stopxcell()
            context.startxcell()
                context(i)
            context.stopxcell()
            context.startxcell()
                context(math.mod(2*i*i,10))
            context.stopxcell()
        context.stopxrow()
    end

Wolfgang