Private brackets(0 to 3,0 to 1)
Private intervals(0 to 1,0 to 1)

sub Init
	brackets(0,0) =   6000: brackets(0,1) = 0.17
	brackets(1,0) =  25000: brackets(1,1) = 0.30
	brackets(2,0) =  75000: brackets(2,1) = 0.42
	brackets(3,0) = 150000: brackets(3,1) = 0.47

	intervals(0,0) =     0: intervals(0,1) = 0.015
	intervals(1,0) = 50000: intervals(1,1) = 0.025
end sub

function IncomeTax(amount)
	Init()
	value = 0
	lastRatio = 0
	for c = 0 to 3
		threshold = brackets(c,0)
		ratio = brackets(c,1)
		delta_ratio = ratio - last_ratio
		t = amount-threshold
	if t <= 0 then
			IncomeTax = value
			exit function
		end if
		value = value + (delta_ratio*t)
		last_ratio = ratio
	next
	IncomeTax = value
end function

function Medicare(amount)
	Medicare = amount * 0.015
	if(amount >= 50000) then Medicare = amount * 0.025
end function

function TaxedIncome(amount)
	TaxedIncome = amount-IncomeTax(amount)-Medicare(amount)
end function

function TaxedIncome_partyear(amount,ratio)
	TaxedIncome_partyear = TaxedIncome(amount/ratio)*ratio
end function

function min(a,b)
	if a<b then min = a else min = b
end function

function untaxed(taxed)
	bpos = 0
	ipos = 0
	x = 0
	y = 0
	tax = 0
	med = 0
	
	Init
	do while true
		max = taxed*10  ' This is cheating but hey
		if bpos <= ubound(brackets) then max = min(max,brackets(bpos,0))
		if ipos <= ubound(intervals) then max = min(max,intervals(ipos,0))
		untaxed = (taxed-y)/(1-tax-med)+x
		if untaxed <= max then exit function
		
		i = 0
		if ipos <= ubound(intervals) then
			if bpos > ubound(brackets) then
				i = 1
			else
				if intervals(ipos,0) < brackets(bpos,0) then i = 1
			end if
		end if
			
		if i = 1 then
			x2 = intervals(ipos,0)
			newtax = intervals(ipos,1)
			ipos = ipos + 1
			y = y + (x2-x)*(1-tax-med)-(newtax-med)*x2
			x = x2
			med = newtax
		else
			x2 = brackets(bpos,0)
			newtax = brackets(bpos,1)
			bpos = bpos + 1
			y = y + (x2-x)*(1-tax-med)
			x = x2
			tax = newtax
		end if
	loop
end function

function untaxed_partyear(taxed,ratio)
	untaxed_partyear = untaxed(taxed/ratio)*ratio
end function