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GradedLieAlgebras :: generalExpressionLie

generalExpressionLie -- checks if an expression is of right input form for e.g. relations

Synopsis

Description

An expression is a general Lie expression if it is either a monomialLie or of the form {{coefs},{liemons}}, where coefs belong to L.field and liemons are monomialLie, not [], of the same weight and sign. As coefficients one may always use an integer or a quotient of integers with non-zero denominator in the field. See How to write Lie elements.

i1 : L = lieAlgebra({a,b,c},{},genSigns=>{1,1,0},field=>frac(ZZ/5[x]))

o1 = L

o1 : LieAlgebra
i2 : generalExpressionLie{{1,2},{[a,b],[a,c]}}
the input is not sign-homogeneous

o2 = false
i3 : generalExpressionLie{{1,2},{[a,b],[a,b,c]}}
the input is not weight-homogeneous

o3 = false
i4 : generalExpressionLie{{1/3,2*x-1},{[a,a,b],[a,c,c]}}

o4 = true

See also