More careful proofread should be done. Simple careless mistakes are ubiqutous. Just name a few: "each to other," "plays the important role," "appropriative," "more close" etc. (They might be "with each other," play an important role," "appropriate," "closer." Also English expression is redunadant. For example, "W(t-1) and W(t) are weights of rule that are used at time moments t-1 and t, respectively,' is enough to be like, "W(t) "is weight at timet" or" 0