//Expose indexes signature(anonymous):
    a:: [(string, string, num)]; byName <- index(0); byCity <- index(1);
        byNameAndCity <- index(0, 1).
    
//Expose index signature(named)
    type Record = 
        {
            name:: string, 
            city:: string,
            age:: num
        }.
    
    b:: [Record]; byName <- index(Record.name).

//Use determined index
    x = a["Rabat"]:: Record; index(byCity).

//Determined syntax(view)
    viewByCity = a:: [Record]; index(byCIty).
    x = viewByCity["Rabat"].

//Determined index(inline)
    x = a[byCity: "Rabbat"]:: Record.

    
//Undefined index
    x = a[{city: "Rabat"}] :: Record. <- index byCity should be deduced
    x = a[{name: "Hind", city: "Rabat"}]