700.4. If a permanent is indestructible, rules and effects can’t destroy it. (See guideline 701.6, “Destroy.”) These types of permanents aren't destroyed by deadly damage, and additionally they disregard the lethal-damage state-based action (see guideline 704.5g). Guidelines or impacts might cause an indestructible permanent to-be sacrificed, placed into a graveyard, or exiled."
The guidelines for demolish claims:
701.6. Destroy 701.6a To destroy a permanent, go it from battleground to its owner’s graveyard. 701.6b The actual only real techniques a permanent is destroyed are due to a result that uses your message “destroy” or because of the state-based activities that check for life-threatening harm (see guideline 704.5g) or harm from a source with deathtouch (see rule 704.5h). If a permanent is placed into its owner’s graveyard for any various other reason, this hasn’t already been “destroyed.”
If a creature dealt damage that way would die this turn, exile it rather