You are right, the regular/context-free comment was a typo. You are also correct about c being non-context-free[0]. I have just seen many explanations of langua

You are right, the regular/context-free comment was a typo. You are also correct about c being non-context-free[0]. I have just seen many explanations of language hierarchy online mistaking type-checking for language complexity that it is a pet peeve of mine. [0] http://eli.thegreenplace.net/2007/11/24/the-context-sensitivity-of-cs-grammar http://eli.thegreenplace.net/2007/11/24/the-context-sensitiv...