aoqi@0: x instanceof f: true
aoqi@0: x instanceof b: true
aoqi@0: y instanceof f: true
aoqi@0: y instanceof b: true
aoqi@0: 
aoqi@0: Changing prototype
aoqi@0: 
aoqi@0: x instanceof f: false
aoqi@0: x instanceof b: false
aoqi@0: y instanceof f: false
aoqi@0: y instanceof b: false
aoqi@0: Bound function prototype
aoqi@0: 
aoqi@0: f.hasOwnProperty('prototype'): true
aoqi@0: b.hasOwnProperty('prototype'): false