Solve is a type of Understand. Solve is a synonym of Clear. Clear is a type of Vanish. 
Pain is a synonym of Effort. Thinking requires Effort. one thing you do when you Thinking is Concentrate. 
Understand <--IsA-- Solve <--Synonym--> Clear --IsA--> Vanish 
Pain <--Synonym--> Effort <--HasPrerequisite-- Thinking --HasSubevent--> Concentrate 