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3.4 Variables

The syntax of Pedro variables fall into two categories.

  1. An upper case letter or “_” followed by any sequence consisting of “_” and alphanumeric characters.


              X, X_23, _fred_12
  2. The “anonymous” variable “_”

Note that repeated occurrences of a variable token of the first category in a string representing a Pedro term represent the same variable. This is not the case for anonymous variables: each occurrence represents a different variable.