function xprime=input_rectifier(t,X) 
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%%%%% Program written by Stathis Skouras, April 2002.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% Number of stages in the rectifying section 
Nr=51;

% Total number of 'stages'  
NT=Nr+2;                               % including reboiler and top vessel 

% Inputs
VB=5;                                  % Boilup (kmol/hr)
L0=VB;                                 % Nominal liquid flows in both sections of the column (kmol/hr)

% Store all inputs
U(1)=VB; U(2)=L0; 
xprime=rectifier(t,X,U);
t