Exercise is related to Hard. Hard is related to Description. Description is related to Broad. Broad is related to Stroke. 
you would Grin because Funny. Funny is related to Comedy. 
Exercise <--RelatedTo--> Hard <--RelatedTo--> Description <--RelatedTo--> Broad <--RelatedTo--> Stroke 
Grin --MotivatedByGoal--> Funny <--RelatedTo--> Comedy 