Potomac River

Deductions

• watercourse is for example Potomac River ⇐ (Potomac River is a watercourse), (is a is inverse of is for example)
• Potomac River is a watercourse ⇐ (stream is subclass of watercourse), (Potomac River is a stream)
• stream is for example Potomac River ⇐ (Potomac River is a stream), (is a is inverse of is for example)
• Potomac River is a stream ⇐ (river is subclass of stream), (Potomac River is a river)
• river is for example Potomac River ⇐ (Potomac River is a river), (is a is inverse of is for example)