Test: Compare the expression check.expr evaluated in the student's environment with the solution correct.expr

check.expr(
check.expr,
correct.expr,
failure.message = "{{check_expr}} has the wrong values!",
success.message = "Great, {{check_expr}} seems correct.",
part = NULL,
ps = get.ps(),
stud.env = ps$stud.env, verbose = FALSE, unsubst.check.expr = NULL, unsubst.correct.expr = NULL, str.check.expr = NULL, str.correct.expr = NULL, tol = .Machine$double.eps^0.5
)

## Arguments

check.expr the expression to be checked the correct expression a variable name or vector of variable names shall existence be checked (similar length, class, values) a message that is shown if the variable does not exists (similar the other failure.??? variables) a text that will be added to all failure messages