APL came before all of those. J/K are decendants of APL. Those languages that you used are copying APL features. Some of it is not too bad, but they don't h

APL came before all of those. J/K are decendants of APL. Those languages that you used are copying APL features. Some of it is not too bad, but they don't have the entire power. In J for example, you could factor your code out. The way you factor mathematics. Their power lies in their notation. Outside of the notation, If you have a multidimensional array, you can operate on ranks of it. You can write loopless code, you don't need for, do, while loops. The compounding and combining of verbs allows for a very functional style of programming that you can never realize in the languages you mentioned. You have to understand APL was designed for describing algorithms before it got turned into a computer language.