Question about " so is the tree inclined" and "the tree is inclined"
1. "As a twig is bent, so is the tree inclined."
2. "As a twig is bent, the tree is inclined?"

I suppose that the second half in sentence 2 could be incomplete, which might be written like this, "the tree is inclined to bent." Do you think so? Thank you!

Question

Question about " so is the tree inclined" and "the tree is inclined"
1. "As a twig is bent, so is the tree inclined."
2. "As a twig is bent, the tree is inclined?"

I suppose that the second half in sentence 2 could be incomplete, which might be written like this, "the tree is inclined to bent." Do you think so?  Thank you!

Answer

Sentence two is not incomplete but the absence of "so" changes its meaning.  Without the "so", it is no longer a comparison of the actions of the tree and twig, it becomes an expression of the act.

Your suggestion should be:  "the tree is inclined to bend" although that doesn't give the same meaning.      "Bent" is the past participle, not the infinitive verb.