Analytic combinatorics (the rubric where mathematicians would want to place all the region-of-convergence, zeros-poles, etc. analysis of generating functions–formal power/Laurent series–Z transforms that engineering often focuses on) is not exactly easy-going either. Other common methods (relating convolution to multiplication, inverting transforms etc.) would traditionally be comprised under the Operational Calculus of Mikusiński.

I forgot to mention the converse also applies. Mathematicians talking about stuff we engineers learned the paint by numbers way makes our heads hurt!