This form allows iteration over sequences, collecting nested lists as the final result. Each sequences group of [id seq-expr] starts a new level of nesting. When the * is present at the beginning of a group, its bindings are evaluated in sequence (like let* and for*/list), otherwise they are evaluated in parallel (like let and for/list).

This form is equivalent to:

except when a group of [id seq-expr] starts with a *, then for*/list is used for that group instead of for/list.