It would be a rare-face-to-face encounter between diplomats of the two countries, which have not had formal relations in 30 years.

VOA: standard.2009.09.11

4 So this is 16 times 4 equals 64 and though this is not proof by any means, it's not a formal proof because here is one example that happens to prove my point.

所以是16*4，即,尽管如此，这并不是严格的证明,因为是这个例子碰巧证明了我的观点。

哈佛公开课 - 计算机科学课程节选

Students are really learners, they may not be the students in a formal sense.

学生就是学习者,他们可以不是正式的学生。

麻省理工公开课 - 媒体、教育、市场课程节选

The Palestinians say they will be there too, but they say the meeting does not signal a formal resumption of peace talks.

VOA: standard.2009.09.19

South Korean officials have demanded a formal apology from the North and say they have not yet decided whether and how to pursue the matter further.

VOA: standard.2009.09.11

"It is not a good thing for senior officers to be making derogatory remarks about their commanders, their political superiors, in any kind of setting, certainly not in a formal setting and certainly not when the news media are present."

VOA: standard.2010.06.22