Error in swirlExpectation(condition(object)) :
could not find function "is_equivalent_to"
I didn't realize that you were using R Programming Alt. Unfortunately R Programming Alt is no longer supported. Please use R Programming instead.
说是R Programming Alt已经不再支持了， 所以我们在导入swirl的课程时不要选 R Programming Alt，换成R Programming 就ok了.
