Using ahead bars for calculating current bar indicator

Hello,

I always thought that in ProRealTime I could not use the the values of bars of next week (d+5), next month (d+20) and so on, for calculating the current bar (d) of a calculated indicator.

However, I am surprised to see that in the Darvas boxes indicator bellow, PRT is able to do so.

In an uptrend ticker, the top-left corner of a box is derived from the highest value of a bar some days ahead. How can this be possible.

Could you please explain the mechanism used?

Thank you in advance

Vicente

k=48
once tth=undefined
once ttl=undefined
n=(k*2)-4
p=(n/2)-1

h1=dpo[n](high)
moyh=high-h1
hi=(moyh-moyh[1]+(high[p])/n)*n
hi=(round(hi*100))/100

l1=dpo[n](low)
moyl=low-l1
lo=(moyl-moyl[1]+(low[p])/n)*n
lo=(round(lo*100))/100

low1=(round(low*100))/100
high1=(round(high*100))/100

if barindex > 100 then
if box=1 and (high1>tth or low1<ttl) then
box=0
flag=0
endif
if box=0 and flag=0 and low1<=lo[46] and low1<=lo[45] and low1<=lo[44] then
th=low1
flag=1
endif
if box=0 and flag=1 then
for zz=0 to 44
if  lo[47-zz-1]<th or lo[47-zz-2]<th or lo[47-zz-3]<th then
flag=0
break
endif
if hi[47-zz]>hi[47-zz-1] and hi[47-zz]>hi[47-zz-2] and hi[47-zz]>hi[47-zz-3] then
box=1
ttl=th
tth=hi[47-zz]
break
endif
next
endif
else
tth=undefined
ttl=undefined
endif

if box=1 then
ba=ttl
else
ba=tth
endif

return ba coloured by box-1, tth coloured by box-1, ttl coloured by box-1

Darvas.png