Transposes

$(A^{\mathrm{T}}{)}_{ij}=A_{ji}$

Given any matrix $R$ the product $R^{\mathrm{T}}R$ is always Symmetric Matrix, which means the transpose of a matrix equals itself, because $(R^{\mathrm{T}}R{)}^{\mathrm{T}}=R^{\mathrm{T}}(R^{\mathrm{T}}{)}^{\mathrm{T}}=R^{\mathrm{T}}R$.