I am writing a subordinate clause in the "Related Work" section of my academic paper. Which is correct?
In [1], Smith et al. pointed out that the solution is feasible.
OR
In [1], Smith et al. pointed out that the solution was feasible.
I am quite confused.
On the one hand, I remember clearly the verb tense in the "that" clause should follow that of the verb in the main sentence. Hence, "was" should be used, following "pointed".
On the other hand, Smith's work is always there and always thinks that the solution is feasible. Hence, the present tense should be used.
Which reasoning is correct?
(NOTE: The OP is asking if it is obligatory that the "is" verb is backshifted into "was", or if backshifting is not allowed, or if backshifting is optional. -- F.E.)