Detailed instructions for working a group puzzle of type 'Mathilde'

This is a signature puzzle named 'Mathilde'

The 8 elements in each group of this type of puzzle are: M, A, T, H, I, L, D, and E.

Every group in the puzzle must contain exactly this set of elements.

Each row is a group numbered as shown in this Mathilde figure.

In a Mathilde puzzle, each row is a group numbered as shown in the figure above.

Each column is a group numbered as shown in this Mathilde figure.

In a Mathilde puzzle, each column is a group numbered as shown in the figure above.

Each 4x2 rectangle is a group numbered as shown in this Mathilde figure.

In a Mathilde puzzle, each 4x2 rectangle is a group numbered as shown in the figure above.