chore: remove redundant words

docs/injections/injections.tex

@@ -439,7 +439,7 @@ \subsection{Order-Sorted Regularity (or pre-regularity?)}
 we have:
 \begin{enumerate}
 \item $N$ is a simple sort name (identifier);
-\item $N_i$ is is a $\{P_1,\ldots,P_k\}$-sort-name, $i=1,\ldots,k$.
+\item $N_i$ is a $\{P_1,\ldots,P_k\}$-sort-name, $i=1,\ldots,k$.
 \end{enumerate}
 \begin{lemma}
 Let $N$ be a $P$-sorted-term, where $P=\{P_1,\ldots,P_k\}$ denotes the set of parameters occuring in $N$. If $\theta,\theta':P\to S^{\rm osa}$ such that $\theta(N)\le\theta'(N)$, then $\theta(P_i)\le \theta(P'_i)$ for $i=1,\ldots,n$.

kore/src/Kore/Validate/AliasVerifier.hs

@@ -91,7 +91,7 @@ lookupParsedAlias name =
 
 {- | Verify and add the named alias to the current module.
 
-The alias is fetched from the cache, if available; otherwise is is verified and
+The alias is fetched from the cache, if available; otherwise is verified and
 cached.
 -}
 verifyAlias :: Id -> AliasVerifier ()