that constitutional guarantee is not violated by a reasonable classification based upon substantial distinctions , where the classification is germane to the purpose of the law and applies to all chose belonging to the same class ( peralta vs. comelec , 82 scra 30 [ 1978 ] citing felwa vs. salas , 18 scra 606 [ 1966 ] ; rafael v. embroidery and apparel control and inspection board , 21 scra 336 [ 1967 ] ; inchong etc. , et al .