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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.