iStmt (SBlock stms) = do {
    env <- askEnv;
    store <- getStore;
    runBlock env interpretStmts stms;
  }
iStmt (SBlock stms) = do {
    env <- askEnv;
    store <- getStore;
    runBlock env interpretStmts stms;
  }
iStmt (SBlock stms) = do {
    env <- askEnv;
    store <- getStore;
    runBlock env interpretStmts stms;
  }