# Harmonic integral

Calculus Level 4

$\large \int_{-1/2}^0 H_ x \, dx = \dfrac ab \gamma - \dfrac cd \ln \pi$

If the equation above holds true for positive integers $$a,b,c$$ and $$d$$ with $$\gcd(a,b) = \gcd(c,d) = 1$$, find $$a+b+c+d$$.

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