Calculus
∫nm1tdt\(\int\)_{n}^{m}\(\frac{1}{t}\)dt
∫1m1tdt+∫1n1tdt\(\int\)_1^{m}\(\frac{1}{t}\)dt+\(\int\)_1^{n}\(\frac{1}{t}\)dt
∫mn1tdt\(\int\)_{m}^{n}\(\frac{1}{t}\)dt
∫1mn1tdt\(\int\)_1^{mn}\(\frac{1}{t}\)dt