I'm confused about this issue.
approve function states
Allow _spender to withdraw from your account, multiple times, up to the _value amount.
If I'm understanding this correctly then it means that amount of what _spender is allowed to transfer will stay the same till this function is called again and _value changed.
But then description of
the amount which _spender is still allowed to withdraw from _owner
Which makes me think that allowance gets reduced after each transfer? Or it just mens that even if _spender is allowed to spend 1000, he actually will be able to spend only x if the x is current balance and it is less than 1000?