Conditional constraint if else in JuMP

[odow]

@jmatovu

@NLconstraint(model, eq[i in I], 2y[i]^3 - 1, if x0[i]>=0

This is not a constraint. Do you mean

@NLconstraint(model, eq[i in I; x0[i] >= 0], 2y[i]^3 - 1 == x0[i])

which is equivalent to

for i in I
    if x0[i] >= 0
        @NLconstraint(model, 2y[i]^3 - 1 == x0[i])
    end
end