please i want to help me because this week my presentation and thanks so much
this is my expression :
(row3.Nature_tarification =="F"? row2.INDEX*row3.Montant_fixe
:row2.INDEX<21? row2.INDEX*row5.Montant
:row2.INDEX<41? row2.INDEX*row12.Montant
:row2.INDEX<71&&row13.Nature_tranche =="F"? row2.INDEX*row13.Montant
:row2.INDEX<71&&row13.Nature_tranche =="V"? (40*row20.Montant)+((row2.INDEX-40)*row22.Montant)
:row2.INDEX<101&&row16.Nature_tranche =="F"? row2.INDEX*row16.Montant
:row2.INDEX<101&&row16.Nature_tranche =="V"? (40*row20.Montant)+(30*row22.Montant)+((row2.INDEX-71)*row24.Montant)
:row2.INDEX<151&&row13.Nature_tranche =="F"? row2.INDEX*row17.Montant
:row2.INDEX<151&&row13.Nature_tranche =="V"? (40*row20.Montant)+(30*row22.Montant)+((row2.INDEX-71)*row24.Montant)
:row2.INDEX<501&&row13.Nature_tranche =="F"? row2.INDEX*row14.Montant
:row2.INDEX<501&&row13.Nature_tranche =="V"? (40*row20.Montant)+(30*row22.Montant)+((row2.INDEX-71)*row24.Montant))


""i want to say :
if index = F the result index *montant fixe
else
if index<21 the result  INDEX*Montant
else
if index<71  and  Nature_tranche =="F" the result   row2.INDEX*row13.Montant
else..........""

type index=float
all motant =float
the result =float
nature=string
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thanks