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Expressions

The core data type in Nexus is Expr[A]: expressions. An Expr[A] is a symbolic expression that conceptually holds data of type A.

Analogous types in other libraries

Expr is similar to

• tf.Tensor:
• torch.autograd.Variable (before PyTorch 0.4.0):

An expression Expr[A] in Nexus can be one of the following:

• Input[A]: Symbolic input of type A.
• Const[A]: Constant.
• Param[A]: A parameter that will be updated while training.
• AppN[A] (N = {1, 2, 3}): Result of applying a $N$-ary function.