you are likely to find Potato in/at/on Army. Army is related to Dangerous. 
Ugly is the opposite of Beautiful. Mathematics can be Beautiful. Mathematics is related to Math. Math is related to Sum. 
Potato --AtLocation--> Army <--RelatedTo--> Dangerous 
Ugly <--Antonym--> Beautiful <--HasProperty-- Mathematics <--RelatedTo--> Math <--RelatedTo--> Sum 