[Closed] Question : does parentheses change script behavior?

hi i wrote this code which do offset a selected spline twice and delete the two new segmets that connects them here is the code :

aao = $

w = 3.5

fn deleteoffset spl = (

convertToSplineShape spl

subobjectLevel = 2

todel = numSegments spl 1

todel2= todel/2

sel = #()

setSegSelection spl 1 #()

for i = 1 to todel2 do (

append sel i

)

append sel todel

setSegSelection spl 1 sel

splineOps.delete spl

updateshape spl

)

aa = copy aao

spl = getSplineSelection aa

allspl = numSplines aa

for i = allspl to 1 by -1 do (

if i != spl[1] do (

deleteSpline aa i

)

)

applyOffset aa w

select aa

deleteoffset aa

aa2 = copy aa

applyOffset aa2 (w *-1)

select aa2

deleteoffset aa2  

here is the result :

this is when things get strange if i add two parentheses at the last section of the code :

(

applyOffset aa w

select aa

deleteoffset aa

aa2 = copy aa

applyOffset aa2 (w *-1)

select aa2

deleteoffset aa2

)

this is the result :

can anybody explain it and suggest a fix ? i want to add this code to a forloop or inside a macroscript.
thanks