Check of Sign - mkraska/meclib GitHub Wiki
Procedure based on this forum discussion.
This check is implemented in the feedback function fb_unit.
Question variables
ra(x,y):=stack_units_nums(stack_unit_si_to_si_base(x))/stack_units_nums(stack_unit_si_to_si_base(y));
When checking the sign of symbolic expressions, you might want to assume that any variable in the expression is positive.
map(lambda ([x], assume(x>0)),listofvars(expression));
PRT
This example is in the context of a unitless question design but input with units.
Field | Value |
---|---|
Answer test | AlgEquiv |
SAns | is(ra(S_A, A)>0) Answer S_A is made unitless by dividing it by the model solution |
TAns | true |
true feedback | Das Vorzeichen stimmt. |