diff --git a/src/libpcp/lib.rs b/src/libpcp/lib.rs
index 801b751..4a0b1b5 100644
--- a/src/libpcp/lib.rs
+++ b/src/libpcp/lib.rs
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//! Constraint programming is a declarative programming paradigm mainly used to solve combinatorial problems where you state what constraints a solution must fullfil instead of explaining how to solve it (see README.md).
+//! Constraint programming is a declarative programming paradigm mainly used to solve combinatorial problems where you state what constraints a solution must fulfill instead of explaining how to solve it (see README.md).
 //! A very classic introductory problem to constraint programming is the [N-Queens puzzle](https://en.wikipedia.org/wiki/Eight_queens_puzzle): the goal is to align N queens on a chessboard of size N*N such that no queen can attack each other.
 //! In PCP, we can solve this problem as follows:
 //! ```rust
diff --git a/src/libpcp/logic/boolean_neg.rs b/src/libpcp/logic/boolean_neg.rs
index bf44e59..3d463a9 100644
--- a/src/libpcp/logic/boolean_neg.rs
+++ b/src/libpcp/logic/boolean_neg.rs
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// This class implements the negation of boolean value (not arbritrary formula, for which the negation can be obtained with `f.not()`).
+/// This class implements the negation of boolean value (not arbitrary formula, for which the negation can be obtained with `f.not()`).
 
 use trilean::SKleene;
 use kernel::*;
diff --git a/src/libpcp/variable/memory/trailed.rs b/src/libpcp/variable/memory/trailed.rs
index 740f4a8..8c949d3 100644
--- a/src/libpcp/variable/memory/trailed.rs
+++ b/src/libpcp/variable/memory/trailed.rs
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 
-// TODO: Redo unecessary? By recomputation?
+// TODO: Redo unnecessary? By recomputation?
 //  Investigate why it became slow again...
 //  Turn TrailingStore into a store and not a memory.
 //  Add different store for NonFailure/StrictMonotonicity/... : First implement Derive(...) and see the inheritance system.