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Kripke Platek's user avatar
Kripke Platek's user avatar
Kripke Platek's user avatar
Kripke Platek
  • Member for 3 years, 8 months
  • Last seen more than a week ago
20 votes
1 answer
685 views

Theorem about multiplicity set of continuous functions.

10 votes
4 answers
774 views

false proof of $\root \of 4$ is irrational.

6 votes
5 answers
871 views

Condition for inverse function.

6 votes
3 answers
364 views

Motivation behind Generic filters in forcing.

5 votes
1 answer
455 views

Proving that L1 and L2 have the same theorems.

4 votes
2 answers
404 views

Prove that a wff built up only with $\lnot$ and $\leftrightarrow$ is a tautology iff $\lnot$ and each statement letter occur an even number of times.

4 votes
1 answer
561 views

Proving a Replacement Theorem in Proposition Logic formulas.

4 votes
1 answer
78 views

Confusion about a step of a proof of countability of algebraic numbers.

3 votes
2 answers
265 views

Is the wf $B \to \forall x B$ logically valid?

3 votes
1 answer
228 views

Proof that $\root \of k$ is irrational.

3 votes
1 answer
294 views

Is logic circular at the basic level?

3 votes
0 answers
72 views

Reasoning about "implies" truth table. [duplicate]

3 votes
2 answers
178 views

Number of possible inequalities for $n$ variables.

3 votes
1 answer
971 views

Textbook for Fitch-style Natural Deduction.

2 votes
1 answer
114 views

Different ways to define distance and the definition of $\pi$

2 votes
1 answer
186 views

Showing that $\mathscr B$ is a tautology iff $\lnot \mathscr B'$ is a tautology.

2 votes
1 answer
505 views

Relation between Cayley diagram and Abstract Group action.

2 votes
2 answers
410 views

Equation of a circle passing through the intersection of 'two circle' or 'one circle and one line'.

2 votes
2 answers
360 views

Proving the powers of a element are all distinct.

2 votes
1 answer
110 views

Definition of Predicate Calculus.

2 votes
1 answer
203 views

Extension of proposition 2.4-2.7 in Mendelson logic.

2 votes
0 answers
66 views

Attempt of proving "Compactness theorem" in Mendelson Logic.

2 votes
1 answer
173 views

Why the Equality Axioms are considered as logical axioms?

1 vote
1 answer
148 views

Number of possible interpretations for a wf $\mathscr B$

1 vote
0 answers
167 views

Not understanding the solution of exercise 2.39 in Mendelson.

1 vote
0 answers
219 views

Mendelson logic exercise 2.31.e solution attempt.

1 vote
0 answers
68 views

Proving that $(\exists x_i)(\forall x_j) \mathscr B \to (\forall x_j) (\exists x_i) \mathscr B$ is logically valid.

1 vote
0 answers
35 views

Is this a valid way to factorize polynomials? [duplicate]

1 vote
1 answer
111 views

Difference between $\mathscr B$ and $\mathscr B[b_1, ... , b_k]$ in first order logic.

1 vote
1 answer
160 views

Prove that $\mathscr B$ is satisfiable if and only if $(\exists y_1)...(\exists y_n)\mathscr B$ is satisfiable.