Integration with infinite/finite limits as a form of summation in DSP notation for discrete signals
In the absence of any further information, we must assume that tradition plays a role in the numerical implementation.  The language of mathematics implies that an integration is an integration, so we can assume that the trapezoidal rule holds:

$\int_a^b f (x){\mkern 1mu} dx \approx \frac{1}{2}\sum\limits_{k = 1}^{N} {\left( {{x_{k + 1}} - {x_k}} \right)} \left( {f({x_{k + 1}}) + f({x_k})} \right)$

However, the intent of the author is another mitigating factor, so careful reading is required.  There are often some pathological issues of notation, but these are strange.  

After some numerical experimentation, I've found that in general, an integration is an integration, no matter which field of inquiry.  The language of mathematics is universal.