feat: lazy ite branch internalization in grind
#6737
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This PR ensures that the branches of an `if-then-else` term are internalized only after establishing the truth value of the condition. This change makes its behavior consistent with the `match`-expression and dependent `if-then-else` behavior in `grind`. This feature is particularly important for recursive functions defined by well-founded recursion and `if-then-else`. Without lazy `if-then-else` branch internalization, the equation theorem for the recursive function would unfold until reaching the generation depth threshold, and before performing any case analysis. See new tests for an example.
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This PR ensures that the branches of an
if-then-elseterm are internalized only after establishing the truth value of the condition. This change makes its behavior consistent with thematch-expression and dependentif-then-elsebehavior ingrind.This feature is particularly important for recursive functions defined by well-founded recursion and
if-then-else. Without lazyif-then-elsebranch internalization, the equation theorem for the recursive function would unfold until reaching the generation depth threshold, and before performing any case analysis. See new tests for an example.