# tf.assign_sub(ref, value, use_locking=None, name=None)

### tf.assign_sub(ref, value, use_locking=None, name=None)

See the guide: Variables > Variable helper functions

Update 'ref' by subtracting 'value' from it.

This operation outputs "ref" after the update is done. This makes it easier to chain operations that need to use the reset value.

#### Args:

• ref: A mutable Tensor. Must be one of the following types: float32, float64, int64, int32, uint8, uint16, int16, int8, complex64, complex128, qint8, quint8, qint32, half. Should be from a Variable node.
• value: A Tensor. Must have the same type as ref. The value to be subtracted to the variable.
• use_locking: An optional bool. Defaults to False. If True, the subtraction will be protected by a lock; otherwise the behavior is undefined, but may exhibit less contention.
• name: A name for the operation (optional).

#### Returns:

Same as "ref". Returned as a convenience for operations that want to use the new value after the variable has been updated.

Defined in tensorflow/python/ops/gen_state_ops.py.