The disclosure relates to compounds of formula :wherein X1, X2, X3, X4, Y, n, A, and W are as defined in the disclosure, or a salt thereof, or a hydrate or solvate thereof, and to processes for the preparation of these compounds and the therapeutic use thereof. Each sleeve has an outer casing, a conductive inner casing mated to the outer casing, and conductive knurls protruding towards the sleeve center. This checkpoint component can then be employed by an execution engine to restart the program at a point in time captured by the checkpoint component.