{"published":"2017-03-21 16:24:28","provider_url":"https://hatena.blog","categories":[],"provider_name":"Hatena Blog","author_name":"sicp-zemi","height":"190","author_url":"https://blog.hatena.ne.jp/sicp-zemi/","type":"rich","version":"1.0","url":"https://sicp-zemi.hatenablog.jp/entry/2017/03/21/SICP%E3%82%BC%E3%83%9F%E7%AC%AC42%E5%9B%9E","title":"SICP\u30bc\u30df\u7b2c42\u56de","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fsicp-zemi.hatenablog.jp%2Fentry%2F2017%2F03%2F21%2FSICP%25E3%2582%25BC%25E3%2583%259F%25E7%25AC%25AC42%25E5%259B%259E\" title=\"SICP\u30bc\u30df\u7b2c42\u56de - SICP\u30bc\u30df\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","image_url":null,"blog_title":"SICP\u30bc\u30df","blog_url":"https://sicp-zemi.hatenablog.jp/","width":"100%","description":"\u7df4\u7fd2\u554f\u984c4.7 (define (let*->nested-lets exp) (let ((defs (car exp)) (body (cdr exp))) (if (null? (cdr defs)) (list 'let (car defs) body) (list 'let (car defs) (let*->nested-lets (pair (cdr defs) body)))))) by dolicas \u554f\u984c\u6587\u3067\u8a00\u3063\u3066\u308b\u6d3e\u751f\u5f0f\u3067\u3046\u307e\u304f\u3044\u304f\u306f\u305a\uff0e \u7df4\u7fd2\u554f\u984c4.8 (define (let->combination exp) (if (pair? (cadr exp)) (let-\u2026"}