We have assumed that, in the case of each offering and sale of Securities (including, in the case of any offering or sale of Units, with respect to such Units and each of the Securities comprising part of such Units):

the Registration Statement, and any amendments thereto (including post-effective amendments), will have become effective under the Act and, if such Securities constitute Debt Securities, the Indenture will have been qualified under the TIA and such effectiveness or qualification shall not have been terminated or rescinded;

a Prospectus Supplement will have been prepared and filed with the SEC describing such Securities;

such Securities will have been issued and sold in compliance with applicable United States federal and state securities Laws (defined below) and pursuant to and in the manner stated in the Registration Statement and the applicable Prospectus Supplement;

unless such Securities constitute (a) Common Stock or Debt Securities issuable upon exchange or conversion of Securities constituting Preferred Stock, (b) Common Stock or Preferred Stock issuable upon exchange or conversion of Securities constituting Debt Securities, (c) Common Stock, Preferred Stock or Debt Securities issuable upon exercise of Securities constituting Warrants, or (d) Common Stock issuable upon purchase pursuant to Securities constituting Common Stock Purchase Contracts, a definitive purchase, underwriting or similar agreement with respect to the issuance and sale of such Securities will have been duly authorized, executed and delivered by the Company and the other parties thereto;

at the time of the issuance of such Securities, the Company (a) will validly exist and be duly qualified and in good standing under the laws of its jurisdiction of incorporation and (b) will have the necessary corporate power and due authorization and the certificate of incorporation, bylaws or other organizational documents of the Company will be in full force and effect and will not have been amended, restated, supplemented or otherwise altered, and there will have been no authorization of any such amendment, restatement, supplement or other alteration since the date hereof;

the terms of such Securities and of their issuance and sale will have been established in conformity with and so as not to violate, or result in a default under or breach of, (a) the certificate of incorporation and bylaws or other organizational documents of the Company (and, if such Securities constitute Common Stock Purchase Units a part of which comprises securities other than Common Stock Purchase Contracts, each issuer of such securities), (b) any applicable law, regulation or administrative order or any agreement or instrument binding upon the Company (and, if such Securities constitute Common Stock Purchase Units a part of which comprises securities other than Common Stock Purchase Contracts, each issuer of such securities), (c) any requirement or restriction imposed by any court or governmental or regulatory body having jurisdiction over the Company (and, if such Securities constitute Common Stock Purchase Units a part of which comprises securities other than Common Stock Purchase Contracts, each issuer of such securities) and (d)(1) if such Securities constitute Depositary Shares, the applicable Depositary Agreement and the  applicable approval and authorization of the Company relating to such Depositary Shares, (2) if such Securities constitute Debt Securities, the applicable Indenture or the officers’ certificate or supplemental indenture and the applicable approval and authorization of the Company relating to such Debt Securities, (3) if such Securities constitute Preferred Stock, the applicable certificate of designations and the applicable approval and authorization of the Company relating to such Preferred Stock, (4) if such Securities constitute Warrants, the applicable Warrant Agreement and the applicable approval and authorization of the Company relating to such Warrants, (5) if such Securities constitute (or constitute Common Stock Purchase Units a part of which comprises) Common Stock Purchase Contracts, the applicable Common Stock Purchase Contract Agreement and the applicable approval and authorization of the Company relating to such Common Stock Purchase Contracts, (6) if such Securities constitute Common Stock Purchase Units, the applicable Common Stock Purchase Unit Agreement (and, if such Securities constitute Common Stock Purchase Units a part of which comprises securities other than Common Stock Purchase Contracts, any agreement providing for such securities) and any collateral arrangements relating to such Common Stock Purchase Units and any agreement in respect thereof and the applicable approval and authorization of the Company relating to such Common Stock Purchase Units and (7) if such Securities constitute Units, the applicable Unit Agreement and the applicable approval and authorization of the Company relating to such Units;

if such Securities constitute Common Stock, Preferred Stock or Depositary Shares in respect of underlying Preferred Stock, (a) sufficient shares of Common Stock or Preferred Stock, as applicable, will be authorized for issuance under the certificate of incorporation of the Company that have not otherwise been issued or reserved or otherwise committed for issuance and (b) the consideration for the issuance and sale of such Common Stock, Preferred Stock or Depositary Shares established by the Company Board and provided for in the applicable definitive purchase, underwriting or similar agreement (or, if (1) such Common Stock is issuable upon exchange or conversion of Securities constituting Preferred Stock, the certificate of designations therefor; (2) such Common Stock or Preferred Stock is issuable upon exchange or conversion of Securities constituting Debt Securities, the applicable Indenture or officers’ certificate or supplemental indenture relating to such Debt Securities; (3) such Common Stock or Preferred Stock is issuable upon exercise of Securities constituting Warrants, the applicable Warrant Agreement therefor; or (4) such Common Stock is issuable upon purchase pursuant to Securities constituting Common Stock Purchase Contracts, the applicable Common Stock Purchase Contract Agreement therefor) will not be less than the par value of such Common Stock or Preferred Stock or the Preferred Stock underlying such Depositary Shares, as applicable;

if (a) such Securities constitute Common Stock or Debt Securities issuable upon exchange or conversion of Securities constituting Preferred Stock, the actions with respect to such Preferred Stock referred to in paragraph 2 above will have been taken, (b) such Securities constitute Common Stock or Preferred Stock issuable upon exchange or conversion of Securities constituting Debt Securities, the actions with respect to such Debt Securities referred to in paragraph 3 above will have been taken, (c) such Securities constitute Common Stock, Preferred Stock or Debt Securities issuable upon exercise of Securities constituting Warrants, the actions with respect to such Warrants referred to in paragraph 5 above will have been taken, or (d) such Securities constitute Common Stock issuable under Securities constituting Common Stock Purchase Contracts, the actions with respect to such Common Stock Purchase Contracts referred to in paragraph 6 above will have been taken;

if (a) such Securities constitute (or constitute Depositary Shares in respect of underlying) Preferred Stock that is exchangeable or exercisable for or convertible into Securities constituting Common Stock or Debt Securities, the Company will have taken all necessary corporate action to authorize and approve the issuance of such Common Stock or Debt Securities upon exchange or conversion of such Preferred Stock, the terms of such exchange or conversion and related matters and, in the case of Common Stock, to reserve or otherwise commit such Common Stock for issuance upon such exchange or conversion, (b) such Securities constitute Debt Securities that are exchangeable for or convertible into Securities constituting Common Stock or Preferred Stock, the Company will have then taken all necessary corporate action to authorize and approve the issuance of such Common Stock or Preferred Stock upon exchange or conversion of such Debt Securities (including, in the case of Preferred Stock, the filing of a certificate of designations respecting such Preferred Stock with the Secretary of State of the State of Delaware), the terms of such exchange or conversion and related matters and to reserve or otherwise commit such Common Stock or Preferred Stock for issuance upon such exchange or conversion, (c) such Securities constitute Warrants that are exercisable for Securities constituting Common Stock, Preferred Stock or Debt Securities, the Company will have taken all necessary corporate action to authorize and approve the issuance of such Common Stock, Preferred Stock or Debt Securities upon the exercise of such Warrants (including, in the case of Preferred Stock, the filing of a certificate of designations respecting such Preferred Stock with the Secretary of State of the State of Delaware), the terms of such exercise and related matters and, in the case of Preferred Stock or Common Stock, to reserve or otherwise commit such Common Stock or Preferred Stock for issuance upon such exercise, or (d) such Securities constitute (or constitute Common Stock Purchase Units a part of which comprises) Common Stock Purchase Contracts providing for the purchase of Securities constituting Common Stock, the Company will have taken all necessary corporate action to authorize and approve the issuance of such Common Stock upon purchase thereof pursuant to such Common Stock Purchase Contracts, the terms of such purchase and related matters and to reserve or otherwise commit such Common Stock for issuance upon such purchase;

if such Securities constitute Debt Securities, the officers’ certificate or supplemental indenture to the related Indenture establishing and setting forth any terms of such Debt Securities different from those in such Indenture shall not include any provision that is unenforceable against the Company;

if such Securities constitute Warrants, a warrant agreement (the “Warrant Agreement”) relating to such Warrants and not including any provision that is unenforceable against the Company will have been duly authorized, executed and delivered by the Company and a bank or trust company to be selected by the Company, as warrant agent;

if such Securities constitute Depositary Shares, a depositary agreement (the “Depositary Agreement”) relating to such Depositary Shares and the related depositary receipts evidencing such Depositary Shares (“Depositary Receipts”) and not including any provision that is unenforceable against the Company will have been duly authorized, executed and delivered by the Company and a bank or trust company to be selected by the Company, as depositary (the “Depositary”);

if such Securities constitute (or constitute Common Stock Purchase Units a part of which comprises) Common Stock Purchase Contracts, a common stock purchase contract agreement (the “Common Stock Purchase Contract Agreement”) relating to such Common Stock Purchase Contracts and not including any provision that is unenforceable against the Company will have been duly authorized, executed and delivered by the Company and any other party thereto;

if such Securities constitute Common Stock Purchase Units, a common stock purchase unit agreement (the “Common Stock Purchase Unit Agreement” and, with an Indenture, Warrant Agreement, Depositary Agreement, Common Stock Purchase Contract Agreement and Unit Agreement, each, an “Instrument”)  relating to such Common Stock Purchase Units and a Common Stock Purchase Contract Agreement relating to the Common Stock Purchase Contracts comprising a part of such Common Stock Purchase Units and, in each case, not including any provision that is unenforceable against the Company will have been duly authorized, executed and delivered by the Company and any other party thereto;

if such Securities constitute Units, a unit agreement (the “Unit Agreement”) relating to such Units and not including any provision that is unenforceable against the Company will have been duly authorized, executed and delivered by the Company and any other party thereto; and

if such Securities constitute Debt Securities, Depositary Shares, Warrants, Common Stock Purchase Contracts, Common Stock Purchase Units or Units, the applicable Instrument and, if such Securities constitute Warrants exercisable into Debt Securities, the Indenture related to such Debt Securities and, if such Securities constitute Common Stock Purchase Units, the Common Stock Purchase Contract Agreement related to the Common Stock Purchase Contracts comprising a part of such Common Stock Purchase Units, respectively, in each case, will constitute the valid and binding obligation of each party thereto other than the Company, enforceable against each such party in accordance with its terms.

We express no opinion as to the laws of any jurisdiction other than any published constitutions, treaties, laws, rules or regulations or judicial or administrative decisions (“Laws”) of (i) the federal Laws of the United States, (ii) the Delaware General Corporation Law and (iii) the Laws of the State of Texas.

The matters expressed in this letter are subject to and qualified and limited by (i) applicable bankruptcy, insolvency, fraudulent transfer and conveyance, reorganization, moratorium and similar laws affecting creditors’ rights and remedies generally; (ii) general principles of equity, including without limitation, concepts of materiality, reasonableness, good faith and fair dealing and the possible unavailability of specific performance or injunctive relief (regardless of whether considered in a proceeding in equity or at law); and (iii) securities Laws and public policy underlying such Laws with respect to rights to indemnification and contribution.