719.3 Case cards have two special keyword abilities that appear before a long dash and represent a triggered ability and an ability that may be static, triggered, or activated.
719.3a
“To solve — [Condition]” means “At the beginning of your end step, if [condition] and this Case is not solved, this Case becomes solved.”
719.3b
Solved is a designation a permanent can have. It has no rules meaning other than to act as a marker that spells and abilities can identify. Once a permanent becomes solved, it stays solved until it leaves the battlefield. The solved designation is neither an ability nor part of the permanent’s copiable values.
719.3c
If a Case has the solved designation, “Solved — [Ability text]” is an ability that may affect the game if it’s a static ability, it may trigger if it’s a triggered ability, and it can be activated if it’s an activated ability. See rule 702.169, “Solved.”
(refs: 702.169)