.. _op_ai_onnx_If-11:

If - version 11
===============

This page documents version **11** of operator **If**. See :doc:`If` for the latest version (since version 13).

- **Domain**: ``ai.onnx``
- **Since version**: 11

If conditional

**Inputs**

- **cond** (*B*): Condition for the if. The tensor must contain a single element.

**Outputs**

- **outputs** (*V*): Values that are live-out to the enclosing scope. The return values in the ``then_branch`` and ``else_branch`` must be of the same data type. The ``then_branch`` and ``else_branch`` may produce tensors with the same element type and different shapes. If corresponding outputs from the then-branch and the else-branch have static shapes S1 and S2, then the shape of the corresponding output variable of the if-node (if present) must be compatible with both S1 and S2 as it represents the union of both possible shapes.For example, if in a model file, the first output of ``then_branch`` is typed float tensor with shape [2] and the first output of ``else_branch`` is another float tensor with shape [3], If's first output should have (a) no shape set, or (b) a shape of rank 1 with neither ``dim_value`` nor ``dim_param`` set, or (c) a shape of rank 1 with a unique ``dim_param``. In contrast, the first output cannot have the shape [2] since [2] and [3] are not compatible.

**Type Constraints**

- **V**: All Tensor types
  Allowed types: tensor(bool), tensor(complex128), tensor(complex64), tensor(double), tensor(float), tensor(float16), tensor(int16), tensor(int32), tensor(int64), tensor(int8), tensor(string), tensor(uint16), tensor(uint32), tensor(uint64), tensor(uint8).
- **B**: Only bool
  Allowed types: tensor(bool).

Differences with previous version (1)
-------------------------------------

**SchemaDiff**: ``If`` (domain ``'ai.onnx'``)

* old version: 1
* new version: 11
* breaking: no