I guess you're mentioning Greenspun's 10th rule, https://en.m.wikipedia.org/wiki/Greenspun%27s_tenth_rule https://en.m.wikipedia.org/wiki/Greenspun%27s_tenth_ru

I guess you're mentioning Greenspun's 10th rule, https://en.m.wikipedia.org/wiki/Greenspun%27s_tenth_rule https://en.m.wikipedia.org/wiki/Greenspun%27s_tenth_rule: > Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.