A note on a extension of Kreisel's conjecture
		
			V. P. Orevkov		
			Abstract:
			Given a theory  
$\mathfrak{R}$, let 
$\mathfrak{R}\vdash_lA$ means that 
$A$ is provable in
$\mathfrak{R}$ in 
$l$ steps. Let 
$L^*$ be the first order language with a constant
symbol 
$O$, a unary function symbol 
$'$, a binary predicate
symbol 
$=$, ternary predicate symbols 
$P$ and 
$Q$. The theory in
$L^*$ with the axioms 
$\mathbb{R}^*.1$–
$\mathbb{R}^*.13$ defined in §1 of this paper
is denoted by 
$\mathbb{R}^*$. The Robinson arithmetic is obtained from 
$\mathbb{R}^*$
by replacing the predicate symbols 
$P$ and 
$Q$ by the function symbols 
$+$
and 
$\cdot$. Define 
$t^{(n)}$ as 
$n$-times iteration of 
$'$ starting
with 
$t$.
THEOREM. There is a natural number 
$c_1$ such that for any consistent
extension 
$\mathfrak{A}$ of 
$\mathbb{R}^*$ there are a formula 
$A(a)$ and natural
number 
$c_2$ with the following properties: 1) 
$\mathfrak{A}\not\vdash\forall x\,A(x)$,
2) for any natural number 
$n$
$$
\mathbb{R}^*\vdash_{c_1[\log_2(n+1)+c_2]}A(O^{(n)}).
$$	
			
UDC:
			510.66