| ⊦ @(n, n0, n1) ∈ ri ∧ # gndx1 = # lax1 ∧ ri-cons(ri, nodes(gstore ↓, ginval)) ∧ gstore[n] = groupblock(gndx0 + gnd ' + gndx1, lax0 + @(n0, n1) ' + lax1, m0) ∧ inv(groupblock(gndx0 + gnd ' + gndx1, lax0 + @(n0, n1) ' + lax1, m0)) → gnd.nd.key ∈ ri ∧ ri[gnd.nd.key] = @(n, n0, n1) |