MATLAB: How to impelement u1<=u2<=u3 as linear inequality

Question

in my optimizations i have following constraint u1<=u2<=u3 i think i have to use linear equality constaints. ie.Ax<b I am using x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,nonlcon). Any one has any idea? thanks in advance for the help

Answer 1

A=[1 -1 0; 0 1 -1]; b=[0;0];