var isKnownTagName = function() { var cache = {}; return function(tag_name) { if (tag_name in cache) { return cache[tag_name]; } var ret; try { ret = document.createElement(tag_name).constructor != HTMLUnknownElement; } catch(error) { ret …

(define *table* (make-eq-hashtable)) (define boot-object (lambda (object) (if (not (hashtable-contains? *table* object)) (let ((proto (make-eq-hashtable))) (hashtable-set! proto '__proto__ #f) (hashtable-set! *table* object proto))))) (def…