fixed typo into the HPC course

learning/courses/integrating-quantum-and-high-performance-computing/compute-resources.ipynb

@@ -101,7 +101,7 @@
     "\n",
     "In both classical and quantum computing, processes could be executed sequentially or in parallel. Because qubits have a rich state space compared to classical bits, it sometimes makes sense for multiple single-qubit gates to be executed on a qubit in sequence (like an `R_x` gate followed by an `R_z` gate). Since entanglement between qubits is critical to quantum computing, it is also common for a quantum circuit to have a set of entangling gates acting across many qubits. These and other factors make it common to identify processes that can be executed in parallel on the scale of individual gate operations in a quantum circuit. In classical computing, bit-level parallelism is also possible but less commonly considered at the gate level; it is more common to refer to parallel and sequential processes at a larger scale.\n",
     "\n",
-    "In quantum computing, one refers to a \"layer\" of gates which can all be executed simultaneously. In many applications it is useful to perform a set of rotations on all qubits and then entangling gates between pairs of qubits. In these contexts, one refers to a \"rotation layer\" (a layer of gates like `R_x`, `R-y`, and/or `R_z`) and an \"entangling layer\" (like one with `CNOT` gates). The number of layers in a circuit is the \"circuit depth\", an important measure since greater depth means more layers of compounding noise and errors.\n",
+    "In quantum computing, one refers to a \"layer\" of gates which can all be executed simultaneously. In many applications it is useful to perform a set of rotations on all qubits and then entangling gates between pairs of qubits. In these contexts, one refers to a \"rotation layer\" (a layer of gates like `R_x`, `R_y`, and/or `R_z`) and an \"entangling layer\" (like one with `CNOT` gates). The number of layers in a circuit is the \"circuit depth\", an important measure since greater depth means more layers of compounding noise and errors.\n",
     "\n",
     "It can be difficult to identify gate layers visually when the layers are not aligned using barriers. In Qiskit, a barrier serves as an instruction in quantum circuits that acts as a visual separator and a constraint during compilation. Both in drawing the circuit and executing it, no gates will be moved across the barrier. This can be important in contexts like dynamical decoupling, in which one intentionally implements gates that simplify to an identity to suppress certain error types. For more on dynamical decoupling see [this guide](/docs/guides/error-mitigation-and-suppression-techniques). For the visual effect of barriers, compare these two images of the same circuit, the first without barriers and the second with barriers to force alignment of layers.\n",
     "\n",