the concept of "macros" in Mathematica doesn't really exist as its own concept because the whole system is based on rewriting structure. for example, the Replac

the concept of "macros" in Mathematica doesn't really exist as its own concept because the whole system is based on rewriting structure. for example, the ReplaceAll function[1] which is commonly used in idiomatic code is basically an in-place macro definition and execution, yet it wouldn't occur to most people that it's anything special. if you're trying to make a traditional macro, you would implement it as a function with the HoldFirst et al attribute. an important thing to know is that ReplaceAll uses arbitrary structural patterns. it's not a simple "turn every a into b". you can say things like "turn every application of the symbol F on an even number into an application of G on that number divided by two". expr /. F[n_?EvenQ] :> G[n/2] [1] https://reference.wolfram.com/language/ref/ReplaceAll.html https://reference.wolfram.com/language/ref/ReplaceAll.html