7.26 (Basic versus defined symbols in proofs) Treating a symbol as basic, with its own rules, or as a defined symbol, without its own rules, makes a big difference to the complexity of proofs. Use Fitch to open the file Exercise 7.26. In this file, you are asked to construct a proof of-(Av_B) from the premises A and B. A proof of the equivalent sentence AAB would of course take a single step. 7.26 (Basic versus defined symbols in proofs) Treating a symbol as basic, with its own rules, or as a defined symbol, without its own rules, makes a big difference to the complexity of proofs. Use Fitch to open the file Exercise 7.26. In this file, you are asked to construct a proof of-(Av_B) from the premises A and B. A proof of the equivalent sentence AAB would of course take a single step