def get_input_layer_variables(ann, variables, descriptors):
    """
    Given a list of descriptor names and a tuple of
    variables of the MILP_Relu model,
    create and return a dictionary that for each descriptor
    gives the corresponding variable
    """
    # unpack the variables
    x, y, z = variables
    # Initialize an empty dictionary
    sol = dict()
    # Iterate over the input layer and the list of descriptors
    # at the same time
    for v, name in zip(ann.input_layer, descriptors):
        sol[name] = y[v]
    return sol