[Help-glpk] piecewise linear function

[Giovanni Di Stasi]

I am trying to use such functions but I get a syntax error. 

In particular, this is my program, taken by the following book chapter:

https://ampl.com/BOOK/CHAPTERS/20-piecewise.pdf

set ORIG; # origins

set DEST; # destinations

param supply {ORIG} >= 0; # amounts available at origins

param demand {DEST} >= 0; # amounts required at destinations

check: sum {i in ORIG} supply[i] = sum {j in DEST} demand[j];

param rate1 {i in ORIG, j in DEST} >= 0;

param rate2 {i in ORIG, j in DEST} >= rate1[i,j];

param rate3 {i in ORIG, j in DEST} >= rate2[i,j];

param limit1 {i in ORIG, j in DEST} > 0;

param limit2 {i in ORIG, j in DEST} > limit1[i,j];

var Trans {ORIG,DEST} >= 0; # units to be shipped

minimize Total_Cost: sum {i in ORIG, j in DEST}

<<limit1[i,j], limit2[i,j];

rate1[i,j], rate2[i,j], rate3[i,j]>> Trans[i,j];

subject to Supply {i in ORIG}:

sum {j in DEST} Trans[i,j] = supply[i];

subject to Demand {j in DEST}:

sum {i in ORIG} Trans[i,j] = demand[j];

When I try to make glpk parse it, I get the following error:

glpsol --model glpk/Test --data /tmp/DATAg5ZQ0L -w /tmp/OUTXlm0ST

GLPSOL: GLPK LP/MIP Solver, v4.61

Parameter(s) specified in the command line:

 --model glpk/Test --data /tmp/DATAg5ZQ0L -w /tmp/OUTXlm0ST

Reading model section from glpk/Test...

glpk/Test:14: syntax error in _expression_

Context: ...>= 0 ; minimize Total_Cost : sum { i in ORIG , j in DEST } <

MathProg model processing error

I really have no clue as of now.

Thanks