{"action":"created","issue":{"url":"https://api.github.com/repos/snu-sf/pl2015/issues/140","labels_url":"https://api.github.com/repos/snu-sf/pl2015/issues/140/labels{/name}","comments_url":"https://api.github.com/repos/snu-sf/pl2015/issues/140/comments","events_url":"https://api.github.com/repos/snu-sf/pl2015/issues/140/events","html_url":"https://github.com/snu-sf/pl2015/issues/140","id":83930554,"number":140,"title":"Assignment 10_08","user":{"login":"AdamBJ","id":8980400,"avatar_url":"https://avatars.githubusercontent.com/u/8980400?v=3","gravatar_id":"","url":"https://api.github.com/users/AdamBJ","html_url":"https://github.com/AdamBJ","followers_url":"https://api.github.com/users/AdamBJ/followers","following_url":"https://api.github.com/users/AdamBJ/following{/other_user}","gists_url":"https://api.github.com/users/AdamBJ/gists{/gist_id}","starred_url":"https://api.github.com/users/AdamBJ/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/AdamBJ/subscriptions","organizations_url":"https://api.github.com/users/AdamBJ/orgs","repos_url":"https://api.github.com/users/AdamBJ/repos","events_url":"https://api.github.com/users/AdamBJ/events{/privacy}","received_events_url":"https://api.github.com/users/AdamBJ/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-06-02T09:14:32Z","updated_at":"2015-06-02T12:52:20Z","closed_at":null,"body":"I'm  trying to follow the guide for this question: (ie  \r\n             ..\r\n       P (C n1) t2 ==>        (by ST_Plus2)\r\n       P (C n1) t2' ==>       (by ST_Plus2)\r\n       P (C n1) t2'' ==>      (by ST_Plus2)\r\n        ..\r\n       P (C n1) (C n2) ==>    (by ST_PlusConstConst)\r\n       C (n1 + n2))\r\n\r\nBut I'm getting stuck near the end:\r\n\r\n```\r\n3 subgoal\r\nCase := \"P\" : String.string\r\nt2 : tm\r\nn1 : nat\r\nn2 : nat\r\nH0 : t2 || n2\r\nIHeval2 : t2 ==>* C n2\r\ny : tm\r\nH3 : t2 ==> y\r\nH4 : y ==>* C n2\r\ny0 : tm\r\nH7 : y ==> y0\r\nH8 : y0 ==>* C n2\r\nH : C n1 || n1\r\nIHeval1 : C n1 ==>* C n1\r\n______________________________________(1/3)\r\ny ==> C n2\r\n______________________________________(2/3)\r\nP (C n1) (C n2) ==>* C (n1 + n2)\r\n______________________________________(3/3)\r\nP t1 t2 ==>* C (n1 + n2)\r\n```              \r\nH4 tells us that y mutli-steps to C n2, but I need to show y steps to C n2. Is this goal provable? If so, can someone give me a hint about what to do next?"},"comment":{"url":"https://api.github.com/repos/snu-sf/pl2015/issues/comments/107943461","html_url":"https://github.com/snu-sf/pl2015/issues/140#issuecomment-107943461","issue_url":"https://api.github.com/repos/snu-sf/pl2015/issues/140","id":107943461,"user":{"login":"alkaza","id":11328291,"avatar_url":"https://avatars.githubusercontent.com/u/11328291?v=3","gravatar_id":"","url":"https://api.github.com/users/alkaza","html_url":"https://github.com/alkaza","followers_url":"https://api.github.com/users/alkaza/followers","following_url":"https://api.github.com/users/alkaza/following{/other_user}","gists_url":"https://api.github.com/users/alkaza/gists{/gist_id}","starred_url":"https://api.github.com/users/alkaza/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/alkaza/subscriptions","organizations_url":"https://api.github.com/users/alkaza/orgs","repos_url":"https://api.github.com/users/alkaza/repos","events_url":"https://api.github.com/users/alkaza/events{/privacy}","received_events_url":"https://api.github.com/users/alkaza/received_events","type":"User","site_admin":false},"created_at":"2015-06-02T12:52:20Z","updated_at":"2015-06-02T12:52:20Z","body":"I meant you should have used those theorems before this goal. Right after Case \"P\"."}}