2 binary swaps of 2 pairs of edges

2 pairs or edges are swapped, opposite (forming a cross) or adjacent (forming 2 parallel slash).

swap opposite horizontal E1-E4, opposite vertical E2-E3

	y2 M2 U M2 U2 M2 U M2 y2

swap adjacent C2 centered E1-E2, adjacent C3 centered E3-E4

	M2 U M2 U M' U2 M2 U2 M' U2

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