eta.lf.LF

class LF(formula)[source]

Bases: object

Defines an abstract logical form.

A logical form (whether ULF or ELF) must contain a formula, variable bindings, functions for binding/unbinding variables, for replacing variables, and for getting the formula (or a natural language representation thereof) after making all variable assignments.

Parameters:: formula (str or s-expr) – The formula for this logical form (an S-expression or LISP-formatted string representation thereof).

formula

The formula for this logical form.

Type:: s-expr

bindings

A mapping from variables to bound values.

Type:: dict

Methods

`bind`	Bind the given variable symbol to the given value.
`get_formula`	Get the formula, applying any variable assignments first.
`replacevar`	Replace the first variable symbol with the second variable symbol throughout the logical form.
`to_nl`	Convert the formula to a natural language string.
`unbind`	Unbind the given variable symbol.

bind(var, val)[source]: Bind the given variable symbol to the given value.

unbind(var)[source]: Unbind the given variable symbol.

replacevar(var1, var2)[source]: Replace the first variable symbol with the second variable symbol throughout the logical form.

get_formula()[source]: Get the formula, applying any variable assignments first.

to_nl()[source]: Convert the formula to a natural language string.

__str__()[source]: Return str(self).