Bug or feature: IsDefined[] and intersection of lines

hjbortol shared this question 11 years ago

In the input field, type:

x = 1

y = 1

Then, construct the intersection of these two lines (the point A).

In the input field, type


The answer is true.

Now change the equation "y = 1" to "x = 2". The Algebra View shows:

A = undefined

but IsDefined[A] still returns true.

Curiously, IsDefined[] works well with intersection of segments.

Is this behaviour correct?

Thanks in advance, Humberto.

Comments (1)


Fixed - online now

© 2020 International GeoGebra Institute