Excel Lambda functions for array manipulation

EXARR

REPLACENTH = LAMBDA(array, xnew, trow, [tcol],
    LET(
        tcol, MAX(tcol, 1),
        MAKEARRAY(
            ROWS(array),
            COLUMNS(array),
            LAMBDA(irow, icol,
                IF(
                    AND(irow = trow, icol = tcol),
                    xnew,
                    INDEX(array, irow, icol)
                )
            )
        )
    )
);

ARRMAPLAM = LAMBDA(array, transf, [cond],
    MAKEARRAY(
        ROWS(array),
        COLUMNS(array),
        LAMBDA(ir, ic,
            IF(
                IF(
                    ISOMITTED(cond),
                    TRUE,
                    cond(array, ir, ic)
                ),
                transf(array, ir, ic),
                INDEX(array, ir, ic)
            )
        )
    )
);