## WeBWorK Problems

### Error generation issue in a library problem

by Abhijit Dasgupta -
Number of replies: 2
Students are reporting an issue that I am unable to diagnose myself after looking at the problem code.

The second part of the library problem below asks for a slope-intercept equation and if a student uses the letter 'm' instead of the actual numerical value of the slope, they are getting the "There may be something wrong" warning, which is saying:

Use of uninitialized value \$new_rh_ans_evaluation_result in concatenation (.) or string at /opt/webwork/pg/lib/WeBWorK/PG/Translator.pm line 1337

An example illustrating the issue, aka "Steps to reproduce":

Example correct answer for second part:  y - 4 = (-1)*(x - 7)
Student enters:  y - 4 = m*(x - 7)
The issue:  The student gets the above warning
Expected behavior:  Student should be getting the message "Variable 'm' is not defined in this context"

Here is the library problem:

Library/PCC/BasicAlgebra/PointSlopeForm/ParallelPerpendicular170.pg

## DBsubject(Algebra)
## DBchapter(Linear equations and functions)
## DBsection(Equations of lines: general)
## Institution(PCC)
## Author(Alex Jordan, Carl Yao, Chris Hughes)

Our WeBWorK version is 2.14 and  pg_version is PG-2.14.

Thanks,

Abhijit Dasgupta

Tags:

### Re: Error generation issue in a library problem

by Alex Jordan -

First, please try using the Contrib version of the exercise, which may be more up to date:

Contrib/PCC/BasicAlgebra/PointSlopeForm/ParallelPerpendicular170.pg

If your course does not have a link set up to the Contrib folder, you will have to arrange for that first with the server admin.

If the issue persists even with the Contrib version, let me know here and I'll look into it.