When translating a term calculus into a graphical formalism many inessential details are abstracted away. In the case of $\lambda$-calculus translated to proof-nets. these inessential details are captured by a notion of equivalence on $\lambda$-terms known as $\simeq_\sigma$-equivalence. in both the intuitionistic (due to Regnier) and classical (due to Laurent) cases. https://herbsdailyes.shop/product-category/paba/