https://esolangs.org/wiki/Brainfuck

which are too simple to have WTFs, although you might say the whole thing is a WTF. I think AVR-8 assembler is WTF free, but I'd like a more powerful macro assembler which would probably introduce a WTF.

Common Lisp is full of WTFs, I went through many stages of grief reading Graham's On Lisp but most notable was "if he was using Clojure he wouldn't be fighting with nconc". People have problems with Clojure too

https://www.more-magic.net/posts/thoughts-on-clojure.html

   printf( "thing1=%u\n"
           "thing2=%u\n"
           "thing3=%u\n"
           "thing4=%u\n"
           "thing5=%u\n",
       thing1,
       thing2,
       thing3,
       thing4,
       thing5);

ghci> [0, 0.3 .. 2.0] [0.0,0.3,0.6,0.8999999999999999,1.2,1.5,1.7999999999999998,2.1]

I'd rather not see 2.1 in a range up to 2.0