<p>If DTIME(2^n)=PSPACE then DTIME(2^poly)=PSPACE.</p>

<p>But, by the time hierarchy theorem, DTIME(2^n)⊊DTIME(2^poly)  </p>

CC BY-SA 4.0
2018-10-31T09:44:22.423Z
Please don't answer off-topic questions.
Jan Johannsen
CC BY-SA 4.0
2018-10-31T15:49:13.470Z
Is there a meta discussion somewhere regarding this policy? Considering most off-topic questions are here by mistake (and presumably in good faith), I don't see how it hurts anyone to post answers before the question is migrated.
Yonatan N
CC BY-SA 4.0
2018-10-31T09:20:57.943Z
2018-10-31T09:28:38.117Z
2018-10-31T09:28:38.117Z
Avi Tal
<p>Why <span class="math-container">$PSPACE != Dtime(2^n)$</span>? I can not see how padding argument can help here, how can it be proven?</p>

CC BY-SA 4.0
2018-10-31T09:45:05.693Z
I don't understand. What is the factorial of PSPACE?
Jan Johannsen
CC BY-SA 4.0
2018-10-31T10:24:20.200Z
@Jan Johannsen - I assume that it represents the "not equal ≠ " sign in C programming language
Avi Tal
<cc.complexity-theory><pspace>
Why $PSPACE!=Dtime(2^n)$?
student
# Why $PSPACE!=Dtime(2^n)$?

(Asked by: username_0 on 2018-10-31)

Why $PSPACE != Dtime(2^n)$? I can not see how padding argument can help here, how can it be proven?

**Tags:** cc.complexity-theory, pspace
> **Comments:**
> **username_1**: I don't understand. What is the factorial of PSPACE?  
> **username_2**: @Jan Johannsen - I assume that it represents the "not equal ≠ " sign in C programming language  

---

## 1 answers

### Answer by username_2 on 2018-10-31. Score: 3

If DTIME(2^n)=PSPACE then DTIME(2^poly)=PSPACE.

But, by the time hierarchy theorem, DTIME(2^n)⊊DTIME(2^poly)

> **Comments:**
> **username_1**: Please don't answer off-topic questions.  
> **username_3**: Is there a meta discussion somewhere regarding this policy? Considering most off-topic questions are here by mistake (and presumably in good faith), I don't see how it hurts anyone to post answers before the question is migrated.  

---

