X-expressions (as [1]) is simply a subset of S-expressions. [1] https://docs.racket-lang.org/teachpack/2htdpbatch-io.html?q=xepr#%28def._%28%28lib._2htdp%2Fbat

X-expressions (as [1]) is simply a subset of S-expressions. [1] https://docs.racket-lang.org/teachpack/2htdpbatch-io.html?q=xepr#%28def._%28%28lib._2htdp%2Fbatch-io..rkt%29._xexpr~3f%29%29 https://docs.racket-lang.org/teachpack/2htdpbatch-io.html?q=...