Stroke is related to Illness. Stable is a type of Illness. 
Tender is a type of Change. Conversion is a type of Change. Conversion is related to Call. Call is a synonym of Visit. 
Stroke <--RelatedTo--> Illness <--IsA-- Stable 
Tender --IsA--> Change <--IsA-- Conversion <--RelatedTo--> Call <--Synonym--> Visit 