prove:
The 2nd axiom of mathematical logic
2) $((P\implies(Q\implies R))\implies((P\implies Q)\implies(P\implies R))$
By using only the deduction theorem
Given the following axioms:
1) ##P\implies(Q\implies P)##
2) ##((P\implies(Q\implies R))\implies((P\implies Q)\implies(P\implies R))## Where ##P,Q,R## are any formulas
3)##(\neg P\implies\neg Q)\implies (Q\implies P)## then prove:
##\{A\implies B,B\implies C\}|- A\implies C##
Without using the...
AN easy solution:
$x^4+2x^3-x^2-6x-3=x^4+2x^3+2x^2-3x^2-6x-3=x^4+2x^2(x+1)-3(x+1)^2=
(\frac{x^2}{x+1)})^2+2\frac{x^2}{x+1}-3=0$
devide by $(x+1)^2$
The solutions of this quadratic equation are:
because if you put $y=\frac{x^2}{x+1}$ you get the quadratic equation $y^2+2y-3=0$...
Dont you know the basic fact that every rule of inference can be expressed as a conditional whose antecedent is the conjunofnction of premises and whose consequent is the conclusion
You can find that in any book in basic symbolic logic
The above conditional is the conditional of m.ponens...
yes definitely ,particularly the last one where in one post you say that m.ponens is a formula and in another it is not .
By the way which is the book that suports your definition of an inference rule because up to now i am the one that have produced several books as reference.
And because in...