user: I'm working on a project that involves some heavy matrix calculations, and I need to multiply several pairs of matrices to analyze the data. Could you multiply these sets of matrices: [[1, 2, 3], [4, 5, 6], [7, 8, 9]] with [[10, 11, 12], [13, 14, 15], [16, 17, 18]]; [[19, 20], [21, 22]] with [[23, 24], [25, 26]]; [[27, 28, 29, 30], [31, 32, 33, 34]] with [[35, 36, 37, 38], [39, 40, 41, 42]]; and [[43, 44], [45, 46]] with [[47, 48], [49, 50]]?

Available functions:
name: mat_mul
description: Multiplies two matrices.
parameters: type: dict
properties: matA: type: array
description: The first matrix.
items: type: integer
matB: type: array
description: The second matrix.
items: type: integer
required: matA
matB