∑B.S.- ∑F.S = Last R.L.- First R.L. only ∑Rise -∑Fall = Last R.L. - First R.L. only ∑B.S - ∑FF.S = ∑Rise-∑Fall = Last R.L. — First R.L. ∑B.S.- ∑F.s = ∑Rise -∑Fall only
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"Scientists dream about doing great things. Engineers do them."