Traverse the Ulvenwald

• WWizards of the Coast2016-04-08
  Official Ruling
  Some delirium abilities that appear on instants and sorceries use the word "instead." These spells have an upgraded effect when they resolve if there are four or more card types among cards in your graveyard. They check that number only while they're resolving and don't count themselves, since they aren't in your graveyard yet. You only get the upgraded effect, not both effects.
• WWizards of the Coast2025-01-24
  Official Ruling
  Some delirium abilities that appear on instants and sorceries use the word “instead.” These spells have an upgraded effect when they resolve if there are four or more card types among cards in your graveyard. They check that number only while they’re resolving and don’t count themselves, since they aren’t in your graveyard yet. You only get the upgraded effect, not both effects.
• WWizards of the Coast2025-01-24
  Official Ruling
  The number of card types matters, not the number of cards. For example, Epitaph Golem (an artifact creature) along with Memory Deluge (an instant) and Travel Preparations (a sorcery) will enable delirium.
• WWizards of the Coast2025-01-24
  Official Ruling
  The card types that could appear in your graveyard are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Supertypes (such as legendary and basic) and subtypes (such as Human and Equipment) are not counted.
• WWizards of the Coast2025-01-24
  Official Ruling
  Because you consider only the characteristics of a double-faced card’s front face while it’s not on the battlefield, the types of its back face won’t be counted for delirium.
• WWizards of the Coast2025-01-24
  Official Ruling
  The delirium ability of Traverse the Ulvenwald allows you to find a nonbasic land card.

Rulings via Scryfall