The phrase "a graph has been" is correct and usable in written English.
It can be used when discussing the status or condition of a graph, often in the context of analysis or reporting.
Example: "A graph has been created to illustrate the trends in sales over the past year."
Alternatives: "a graph was made" or "a graph has been generated."
Some new fixed-point results for graphic contractions on a complete metric space with a graph have been presented in [8]; also they gave a particular case of almost contractions.
Also, a number of mathematical properties, especially various lower and upper bounds on the Estrada index of a graph have been established, for details we refer the reader to [9 16]; other properties can be found in [17 19] and a latest survey paper by Gutman et al. [20].
Finally, it turned out that the developed information indices for measuring the information content of a graph have been of substantial impact when solving QSPR (Quantitative structure-property relationship)/QSAR (Quantitative structure-activity relationship) problems in mathematical chemistry and drug design [1], [2], [20] [25].
A DAG defining a provenance graph has been utilized to model topic correlations as has been described in [62].
In spite of this, the complexity status of the triangle graph recognition problem (namely, the problem of deciding whether a given graph is a triangle graph) has been the most fundamental open problem on this class of graphs since its introduction two decades ago.
A conflict graph has been conventionally defined as a non-weighted graph.
A bar graph has been chosen as it is the standard presentation format commonly used in current risk prediction tools.
Except for the suggested utilization of the "negotiation dance graph" [56], to date only a "history graph" has been proposed and implemented [27,63].
A different diversity graph has been constructed for each single-carbon environment.
Thus, for each type of analysis, a change in the graph has been determined to determine the Tg.
