Comment 4 for bug 452008

CLHS says "Should be prepared to signal an error of type type-error if sequence is not a proper sequence." which in then means (see 1.4.2) "This is similar to ``should be signaled'' except that it does not imply that `extra effort' has to be taken on the part of an operator to discover an erroneous situation if the normal action of that operator can be performed successfully with only `lazy' checking. An implementation is always permitted to signal an error, but even in safe code, it is only required to signal the error when failing to signal it might lead to incorrect results. In unsafe code, the consequences are undefined."

(Translation: I'm thinking about what we want to do.)

Thanks again for the patch!