> You can generally count on built-in formulas to be correct, which might have to be recreated in a different language; This is wishful thinking at best. Exce

> You can generally count on built-in formulas to be correct, which might have to be recreated in a different language; This is wishful thinking at best. Excel numerics have all sorts of undocumented corner cases that attempt to make answers that “look right” instead of a predictable and documented numerics model. It’s been years since I’ve used Excel, but for example, you can construct values A and B that satisfy any subset of the the following conditions: (1) A == B is true (2) A - B is zero (3) A and B display the same value under any formatting. These tiny differences usually don’t matter, but eventually someone tries to do an unstable computation, and the tiny differences are blown up into great big differences.