Similar but not the same. With dynamic scope, the variable lookup is performed up the chain of environments that the function was called in. The only way that

Similar but not the same. With dynamic scope, the variable lookup is performed up the chain of environments that the function was called in. The only way that you can influence this is by calling the function within a certain scope, you can't explicitly set the scope so it isn't as flexible as Io's scope and it isn't as fast as the lexical scope of most Lisps.