"""Shared, evaluated teaching examples for legends and visual grammar help."""
from functools import lru_cache


@lru_cache(maxsize=2)
def multiplication_example(forward_only=False):
    import sympy as sp
    from autodiff_visualizer import ComputationGraph, safe_parse_expr
    graph = ComputationGraph().build(safe_parse_expr('(x*x)*y'), forward_only=forward_only)
    graph.evaluate({sp.Symbol('x'): 3., sp.Symbol('y'): 4.}, forward_only=forward_only)
    return graph.to_computation_model(forward_only=forward_only)