?> def foo(&blk)
>> lvar = "i am being accessed"
>> instance_eval(&blk)
>> end
=> nil
>> foo { lvar }
NameError: undefined local variable or method `lvar' for main:Object
	from (irb):6
	from (irb):4:in `instance_eval'
	from (irb):4:in `foo'
	from (irb):6
>>