where formula_6 is the learning rate at iteration formula_4, formula_8 is the initial learning rate, formula_3 is how much the learning rate should change at each drop (0.5 corresponds to a halving) and formula_10 corresponds to the droprate, or how often the rate should be dropped (10 corresponds to a drop every 10 iterations). the "floor" function here drops the value of its input to 0 for all values smaller than 1.