Heat Transfer descriptions A Heat Transfer problem is described with equations & shows a Calculus-level language used for solving this two point boundary value problem . The equations being solved may be ordinary differential equations and/or partial differential equations of any order degree. Equations maybe nonLinear implicit any order any degree and/or constrained. Automatic Differentiation coupled with Operator Overloading are the key ingredience for a Calculus-level programming language. Our website introduces the Fortran Calculus language/compiler. The main point is simulating entire company processes distribution systems etc. with an eye on ones company goal. This is accomplished by nesting of simulation problems in one run.